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American  Tool  Making 


AND 


Interchangeable  Manufacturim 


American  Tool  Making 

AND 

Interchangeable  Manufacturing 


A  Treatise  upon  the  Designing,  Constructing,  Use,  and  Installation 
of  Tools,  Jigs,  Fixtures,   Devices,   Special  Appliances,   Sheet- 
Metal  Working  Processes,   Automatic  Mechanisms,   and 
Labor-Saving  Contrivances ;  together  with  Their  Use 
in  the  Lathe,    Milling  Machine,   Turret  Lathe, 
Screw  Machine,  Boring  Mill,  Power  Press, 
Drill,   Sub-Press,  Drop   Hammer,  etc., 
for    the   Working   of    Metals,    the 
Production  of  Interchangeable 
Machine     Parts    and    the 
Manufacture  of  Rep- 
etition Articles 
of  Metal 


By 
JOSEPH   V.  fOODWORTH 

Author  of  "Dies,  Their  Construction  and   Use,"  "Hardening,  Tempering, 
Annealing,  and  Forging  of  Steel,"  etc. 


ILLUSTRATED  BY  SIX  HUNDRED  ENGRAVINGS 

FROM  ORIGINAL  DRAWINGS  BY 

THE  AUTHOR 


NEW    YORK 

THE 

NORMAN 

W.  HENLEY  PUBLISHING 

CO. 

1  3 

2    Nassau    Street 
L905 

im 


tw 


115^ 


Copyright,  1904,  by 

The  Norman  W.  Henley  Publishing  Company 

also  entered  at 
Stationers'  Hall  Court,  London.  England 


All  Rights  Reserved 


oncTON  COLLtbt 


BOSTON 


composition,  electrotyping,  and   presswork  by 
Publishers'  Printing  Company 

New  York,  U.  S.  A.  tUtk    2  5  tQfi& 


PREFACE. 


By  this  preface  I  offer  to  American  tool-makers  a  treatise  on 
their  art — and  mine.  My  reasons  for  this  venture  are  numer- 
ous, but  chief  among  them  is  the  fact  that  to  every  tool -maker, 
every  machinist,  every  worker  in  metals,  a  knowledge  of  what 
can  be  attained  in  his  art  is  to-day  indispensable,  and  the  attain- 
ment of  that  knowledge  should  be  both  easy  and  pleasant. 

This  treatise  is  intended  for  the  man  at  the  head  of  the  shop 
as  well  as  the  man  at  the  lathe ;  for  the  man  who  has  neither  the 
time  nor  the  inclination  to  delve  into  ten  or  twenty  volumes  of 
more  or  less  contradictory  mechanical  dissertation ;  for  the  prac- 
tical man  of  the  drafting-room,  the  tool-room,  the  machine-shop, 
and  the  forge.  The  work  is  dedicated  to  the  work-bench  of  the 
mechanic  and  the  office  of  the  engineer.  It  is  inscribed  to  all 
who  are  interested  in  the  working  of  metals.  If  they  shall  gain 
knowledge  by  its  perusal  the  author  will  be  abundantly  repaid. 

In  the  writing  and  illustrating  of  this  work  I  have  drawn 
upon  the  accumulated  knowledge  gained  through  many  years  of 
practical  experience,  and  have  embodied  in  it  extracts  from  over 
three  hundred  original  articles  contributed  by  myself  to  the 
mechanical  and  the  technical  press.  In  arranging  the  text  and 
the  illustrations  the  following  objects  have  been  constantly  kept 
in  mind: 

I.  To  give  accurate  and  concise  descriptions  of  the  funda- 
mental principles,  methods,  and  processes  by  which  the  greatest 
accuracy  and  highest  efficiency  may  be  attained  in  the  produc- 
tion of  repetition  parts  of  metal  at  the  minimum  of  cost. 

II.  To  discuss  and  illustrate  the  great  numbers  of  special 
tools,  their  construction  and  use,  as  fully  as  possible  within  the 
narrow  limits  of  a  single  volume. 

III.  To  avoid  all  that  is  speculative,  impracticable,  and  ob- 
solete in  processes,  methods,  principles,  design,  and  construction. 


8  PREFACE. 

IV.  To  preserve  a  clear  and  systematic  arrangement  of  the 
numerous  subjects,  giving  to  each  one  its  place  according  to  its 
importance  in  the  treatise. 

V.  To  secure  a  style  and  method  of  presentation  in  the  work 
itself  which  shall  please  the  busy  man  of  metals,  whether  he 
labors  in  the  shop,  the  draughting-room,  the  office,  or  the  labor- 
atory. 

Thus  my  aim  has  been  to  increase  the  practical  knowledge 
and  the  earning  capacity  of  machinists,  tool-makers,  die-mak- 
ers, steel -workers,  blacksmiths,  model-makers,  and  foremen ; 
to  point  out  to  superintendents  where  and  how  to  secure  the 
maximum  of  output  from  the  minimum  of  cost  and  labor;  to 
give  general  managers  and  proprietors  of  metal- working  estab- 
lishments methods  by  which  they  may  increase  the  output  and 
the  income,  and — last,  but  not  least — to  put  into  the  hands  of 
the  earnest  and  intelligent  apprentice  a  text -book  of  the  art  that 
has  gained  for  the  United  States  the  industrial  supremacy  of 
the  world. 

Whether  these  important  ends  have  been  attained,  it  is  not 
for  me  but  for  the  practical  reader  to  decide.  I  have  labored 
earnestly  and  assiduously  to  add  to  the  world's  stock  of  knowl- 
edge and  to  reach  the  ideal  of  what  a  work  of  this  kind  should 
be. 

I  surrender  the  treatise,  thus  undertaken  and  completed,  to 
the  reader,  apologizing  for  nothing  contained  in  it  or  omitted, 
and  asking  of  you  only  a  considerate  judgment  and  just  recog- 
nition of  the  work. 

Joseph  V.  Woodwoeth. 

New  York, 
December,  1904. 


CONTENTS. 


CHAPTER  I. 

The  Inception,  Development,  and  Installation  op  the   Modern  Sys- 
tem op  Interchangeable  Manufacturing. 

pages 
Eli  Whitney — Interchangcability — Interchangeable     Manufacturing 
— Modern  Manufacturing  of  Intricate  Machinery — The  American 
Toolmaker— The  Most  Skilled  Mechanic  in  the  World,  .         .     19-27 

CHAPTER  II. 

Machine  Tools,  Designing,  Tool-Making,  and  Tool-Rooms. 

Machine  Tools — The  Designer — The  Great  Principle  of  Reproduc- 
tion— Functions  of  Jigs  and  Fixtures — Templets — Gauges — Flat 
Jigs — Box  Jigs — Work  that  should  not  be  Jigged — Jigs  for 
Heavy  Work — Cheap  Jigs — Accurate  Jigs — Tool-rooms  and 
their  Equipment, .         .       28-39 

CHAPTER  III. 

Fundamental  Principles,  Processes,  and   Practical   Points   for   Jig 
Design  and  Construction. 

Factors  Involved — The  Locating  and  Holding  Devices — Simple  Drill- 
ing-jigs— Constructing  Simple  Jigs — Processes  of  Accurate  Jig- 
making — The  Button  Method  for  Locating  Drill  Bushing-holes — 
Patterns  for  Castings  to  be  Jigged — Locating  and  Finishing  Drill 
Bushing-holes  in  Large  Jigs — Jig  Work  on  the  Plain  Milling- 
machine — Handling  Large  Jig  Bodies — Jig  Feet,  .         .         .       40-54 

CHAPTER   IV. 

Types  op  Simple  and  Inexpensive  Drilling-Jigs  ;  Their  Construction 

and  Use. 

Two  Types  of  very  Simple  Drilling-jigs — A  Simple  Fourteen-hole 
Drilling-jig — Jigs  for  a  Bracket  and  Bearing — Two  Simple  Drill- 
ing-jigs and  their  Use — Two  Drilling-jigs  for  the  Speed-lathe — 
A  Drill-jig  for  Acetylene  Gas-burners — Drilling-jigs  for  Odd- 
shaped  Castings — Jig  for  Drilling  Rough  Castings  in  Pairs — Jig 
for  Drilling  Cams,  .         .        .        : 55-80 


10  CONTENTS. 

CHAPTER  V. 
Intricate  and  Positive  Drilling-Jigs. 

PAGES 

Jig  for  Drilling  a  Multiple  Cam-body— Drilling  and  Hub-facing  Jig 
— An  Intricate  Jig  for  Typewriter  Bases — Two  Drilling-jigs  for 
Small,  Accurate  Work — Jig  for  Drilling  an  Aluminum  Base 
Casting 81-95 

CHAPTER  VI. 

The  Design  and  Construction  of  Drilling-Jigs  for  Heavy  Machine 

Parts,  etc. 

Constructing  Large  Drilling-jigs — Jig  for  Drilling  a  Nailing-machine 
Cross-head — Drilling-jig  for  Cast-iron  Impression  Rollers — Drill- 
ing-jig for  Dovetailed  Slide  Brackets — Drilling-jig  for  Press- 
bolster — Points  to  be  Remembered, 96-105 

CHAPTER   VII. 

Drilling-Jigs  of  Novel  Design  and  Construction. 

Drilling  Holes  in  a  Spiral  Line  around  a  Cylinder — Indexing  Dial  Jig 
for  Drilling  Small  Cams — Jigs  with  Indexing  Plates — Drilling 
Holes  in  a  Spider  Casting — A  Drilling  and  Tapping  Jig — A 
Novel  Drill-jig, 106-119 

CHAPTER  VIII. 

Use   of   Milling-Machines   for   Modern  Tool-Making,   Interchange- 
able Manufacturing,  and  Jobbing  Shop  Work. 

The  Utility  of  Milling-machines— Improvements  in  Construction — 
Universal  Milling-machines — "Knee  Type"  of  Milling-machines 
— Milling-machines  Compared  with  other  Machine  Tools — The 
Milling-machine  in  the  Tool-room — Milling  an  Angle  Plate — Cir- 
cular Jig-making  on  the  Miller — Vertical  Spindle  Milling-ma- 
chines— Doubt  as  to  the  Utility  of  Milling-machines,   .         .         .  120-128 

CHAPTER   IX. 

Simple  Milling  Fixtures. 

Six  Distinct  Types  of  Simple  Milling  Fixtures— Fixtures  for  Milling 
a  Bearing  in  a  Bracket — Fixture  for  Use  in  Squaring  the  Ends 
of  Duplicate  Pieces — Fixture  for  Use  in  Slotting  and  Dovetail- 
ing Small  Pieces— Fixture  for  Use  in  Gang  Milling— Fixture 
Used  in  Face-milling, 129-140 


CONTENTS.  11 

CHAPTER  X. 
Milling  Fixtures  for  Accurate  Work. 

PAGES 

Factors  in  the  Successful  Use  of  Accurate  Milling  Fixtures— Fixture 
for  the  First  Piece  of  Work — Fixture  for  Use  in  Milling  the  Sec- 
ond Piece — Description  of  Fixture  for  the  Third  Piece — Index- 
ing Milling  Fixture  for  Last  Two  Pieces, 141-151 

CHAPTER   XL 

Miscellaneous  Milling  Fixtures  and  Special  Tools  for  Similar 

Work. 

A  Milling  Fixture  for  Drill-press  Tables — Jig  for  Milling  Drill-press 
Spindle  Heads — Machining  Drill  Columns — Chief  Factor  in  Ma- 
chine Construction,        .........  152-161 

CHAPTER   XII. 

Special  Tools,  Fixtures,  and  Devices  for  Machining  Repetition 
Parts  in  the  Turret-lathe. 

The  Use  of  Special  Fixtures  in  the  Turret-lathe — Attachment  for 
Forming  Irregular  Pieces  from  the  Bar — Box-tool  for  the  Turret- 
head — Two  Special  Chucks  for  the  Turret-lathe — Detail  Sketches 
of  Tools  and  Fixtures  for  Machining  Pulleys — Tools  for  Machin- 
ing a  Special  Casting — A  Multi-spindle  Drilling  and  Tapping 
Attachment  with  Work  Fixture, 162-189 

CHAPTER   XIII. 

Special  Tools,  Fixtures,  and  Devices  for  Machining  Repetition 
Parts  in  the  Screw  Machine. 

Four  Special  Box  Tools  for  the  Screw  Machine —  Screw-machine  Fixt- 
ures and  Tools  for  Making  Speed  Indicators — Method  for  Fin- 
ishing Duplicate  Work  in  the  Screw  Machine — Fixtures  for 
Forming  Pieces  of  Irregular  Outline, 190-207 

CHAPTER  XIV. 

The  Construction  and  Use  of  Boring  Fixtures  and   Similar   Tools. 

The  Drill  Press  and  Boring  Fixtures — Boring  and  Facing  Fixture  for 
"  Sextet "  Castings — Drill-press  Boring-rig  for  Interchangeable 
Work — Special  Machine  for  Boring  Brackets  and  Spindle-heads 
— Boring  Drill-press  Tables — Machining  Round  Tables — Finish- 
ing Cup  Centres — Advantage  in  the  Use  of  Special  Tools,   .         .  208-223 


12  CONTENTS. 

CHAPTER  XV. 

Design  Manufacture  and  Use  of  Milling -Cutters. 

PAGES 

Milling-cutters  Classified — The  Design  and  Manufacture  of  Milling- 
cutters — Standard  Styles  and  Sizes  of  Cutters — Undercut  Teeth 
— End  Mills — Side  Clearance — Inserted  Tooth-cutters — Limits 
of  Inaccuracy — Use  and  Abuse  of  Cutters — Regrinding — Quality 
of  Steel  to  Use  for  Milling-cutters — Selecting  a  Set  of  Cutters  for 
a  Milling-machine — An  Assortment  of  Milling-cutters — Shell  End 
Mills — Spindle  Surface  Mills — Gang  Mills  and  Interlocking  Cut- 
ters— Making  Cutters — Most  Vital  Point  in  Milling-machine  Prac- 
tice— Speeds  and  Feeds  for  Milling-cutters — Suggestions  for  Mill- 
ing   224-238 

CHAPTER   XVI. 

The  Hardening  and  Tempering  of  Milling-Cutters. 

Hardening — Heating- — Plunging — Warping — Lead  Bath — Degree  of 
Hardness — Injury  in  Hardening — Test  for  Hardening — Sand- 
blasting— Heating  and  Hardening  Large  Cutters,         .         .         .  289-243 

CHAPTER   XVII. 

Drills  and  Drilling;  Forming   Tools   and   Facing   Tools;   Counter- 
bores,  Boring  Bars  and  Reamers. 

Deep-hole  Drilling — The  Twist  Drill — Number  of  Cutting  Edges  De- 
sirable— Advantages  of  the  End-cut — Drilling  Holes  by  Pratt 
and  Whitney  Method — Boring  Hollow  Spindles  with  a  Hollow 
Drill — Drill  Notes — Circular  Forming  Tools — Plain  Forming 
Tools — Facing — Counterboring — Counterbores — Reaming  Holes 
in  the  Turret-lathe  —  Reaming  Holes  in  Thin  Discs  —  Machine 
Reaming  with  "Floating"  Reamer — Reaming  Taper  Holes  in 
Cast  Iron — Taper  Reaming  in  the  Screw-machine  —  Reamers 
for  Projectiles — Taper  Rose  Reamers — Centre  Reamers — Ream- 
ers for  Babbitt — Reaming  Holes  in  Two  Kinds  of  Metal — Ma- 
chine Reaming  of  Brass  Parts — Square  Reamers  and  Expansion 
Reamers — "  Home-made  "  Reamers — Hand  Reaming — Increasing 
the  Size  of  a  Reamer  when  Worn, 244-260 

CHAPTER  XVIII. 

Broaches  and  Broaching. 

The  Operation  of  Broaching — An  Interesting  Job  of  Broaching — 
Some  Points  about  Broaches  and  Broaching — Broaching:  Its  Re- 
lation to  Sheet-metal  Work, 261-267 


CONTENTS.  13 

CHAPTER  XIX. 
Shop  Use  of  Micrometer  Calipers  and  the  Height  Gauge. 

PAGKS 

Micrometer  Calipers — Reading  Micrometer  Calipers  to  Ten-thou- 
sandths of  an  Inch — Special  Uses  of  Micrometer  Calipers — The 
Height-gauge  and  its  Use, 268-278 

CHAPTER   XX. 

Mould  Construction. 

Moulds — Moulds  for  Crayon  Pencils — Moulds  for  Lead  Balls — Mak- 
ing Moulds  for  Telephone-receiver  Pieces — How  an  Accurate  Set 
of  Moulds  was  Machined  in  the  Planer — Moulds  for  Bicycle  Han- 
dle Tips— Moulds  for  "  Poker  Chips  "—Spherical  Moulds,    .         .  279-299 

CHAPTER  XXI. 

Special  Tools,  Fixtures,  Devices,  Arrangements,  Contrivances,  and 
Novel  Methods  for  Metal  Working. 

The  Devising  and  Constructing  of  Special  Tools — Making  Thin- 
threaded  Brass  Rings — A  Set  of  Special  Tools  for  Machining  a 
Cam — Cutting  a  Coarse-Pitch  Screw — A  Drill-press  Job — A 
"  Step  Jig  " — A  Drilling  Job  in  the  Planer — A  Spring  Winding 
Fixture — A  Soldering  Face-plate — Making  Collet  Spring  Chucks 
— A  Flaking  Stick— Drilling  Holes  in  a  Helical  Surface — Milling 
in  the  Drill-Press — A  Simple  Lathe  Chuck — Trimming  Sheet 
Brass  Blanks — A  Die-making  Kink — A  Simple  Slotting  Fixture 
— Keyseating  in  the  Power-Press — Hand  Cut-off  and  Forming 
Tool — Milling-Jig  for  the  Speed  Lathe— Jigs  and  Fixtures  for 
Adjustable  Stops  and  Spindle  Racks — Milling  Spindle  Racks- 
Jig  for  Drilling  Small  Thread  Dies, 300-326 

CHAPTER   XXII. 

Special  Tools,  Fixtures,  Devices,  Arrangements,  Contrivances,  and 
Novel  Methods  for  Metal- Working — Continued. 

A  Machine  for  Twisting  Corkscrews — A  Special  Tool  for  Cutting 
Large  Fibre  Washers — An  Unusual  and  Special  Job  of  Tool- 
making — Special  Engraving-Machine — Special  Cam-milling  Ma- 
chine— Chuck  for  Turning  Eccentric  Rings — Chucking  Fixture 
for  Eccentric  Cams — Fixture  for  Chucking  Gasoline-engine  Cyl- 
inders— Special  Milling  and  Drilling  Jigs — A  Set  of  Jigs  for  Mill- 
ing and  Drilling — Facing  and  Counterboring  Large  Spider 
Castings  in  the  Drill-Press,    .  ....  327-354 


14  CONTENTS. 

CHAPTER  XXIII. 
Special  Machines  for  Accurate  Work  on  Dies,  and  Their  Use.- 

PAGES 

Progress  Made  in  the  Use  of  Power-Presses — Hand-Finishing  versus 
Machine-Finishing  of  Dies — Die-sinking  Attachment — Machine 
for  Filing  Dies — Die-shaper — A  Small  Die-slotter — A  Die-filing 
Machine, 355-364 

CHAPTER  XXIV. 

The  Art  of  Sheet-Metal  Working  in  Dies  and  Presses. 

Use  of  Sheet  Metal  in  Place  of  Other  Materials — Simplest  Class  of 
Press  Tools — "Gang  "  and  "Follow"  Dies — Piercing  and  Perfo- 
rating Dies — Processes  of  Drawn  Work — Depth  which  may  be 
Drawn  in  Sheet  Metal — Annealing  and  Lubricating  in  Drawing 
— The  Drawing  and  Forming  of  Decorated  Sheet-metal  Articles 
—"Finding  "  the  Blanks  from  which  to  Draw  Shells,  .         .  365-370 

CHAPTER   XXV. 

The  Making  and  Use  of  Punches  and  Dies  for  Sheet-Metal 

Working. 

The  Making  and  Use  of  Simple  Dies — Punching  Brass  Clock  Gears — 
Movable  Stripping  Devices — Spring  Strippers — Punch  and  Die 
for  End-finishing,  Cutting-off,  and  Bending  Sheet  Metal  from 
the  Strip  without  Waste — Two  Dies  for  Metal  Box-corner  Fast- 
eners— Piercing  and  Spreading  Die  for  Box  Straps — An  Im- 
proved Piercing  Die — Gang  Die  for  Box-Lid  Fastening  Plates 
— Large  Drawing  Dies  for  Circular  Shells — The  Drawing  of 
Deep  Shells  from  Sheet  Metal — Hollow  Cutters  for  Punching 
Leather,  Cloth,  or  Paper, 371-3GS 

CHAPTER  XXVI. 

The  Making  and  Use  of  Punches  and  Dies  for  Sheet-Metal 
Working. — Continued. 

A  Punching  and  Curling  Job — Dies  for  Sheet-metal  Bag  Clasps — A 
Triple-action  Die  for  Blanking,  Drawing,  and  Embossing  an 
Aluminum  Shell  in  One  Operation — Blanking  and  Drawing  an 
Aluminum  Shell — A  Nice  Job  in  Bending  and  Forming — 
"  Gang  "  Punch  and  Die  for  Producing  Eyelets  in  One  Operation 
— Compound  Dies  for  Parts  of  Telephone-transmitter  Cases,        .  399-431 


CONTENTS.  15 


CHAPTER  XXVII. 

Processes,  Presses,  Devices,  and  Arrangements  for  the  Rapid   and 
Economical  Working  op  Sheet  Metals. 

PAGES 

Press  Work — Perforating  Flat  and  Cylindrical  Sheet  Metal— Piercing 
and  Blanking  Small  Armature  Disks — Keeping  Sheets  or  Arti- 
cles Straight  while  Perforating — Perforating  Large  Sheets  of 
Metal  in  Special  Designs — Production  of  Perforated  Metal  by  the 
Allis-Chalmers  Company — Horning  and  Seaming  Processes — 
Curling  and  Wiring  Processes — Manufacture  of  Armature  Disks 
and  Segments, 432-460 

CHAPTER  XXVIII. 

The  Manufacture  of  Accurate  Sheet-Metal  Parts  in  the 
Sub-Press. 

The  Sub-press — Utility  of  the  Sub-press  not  Generally  Understood 
— Principal  Use  of  the  Sub-press — Cost  versus  Longevity  of  the 
Sub-press — How  to  Construct  a  Sub-press—  Setting  Up  and 
Working  a  Sub-press — Action  of  the  Dies — Feeding  of  the 
Metal ' 461-467 

CHAPTER  XXIX. 

Engraving,  Sinking,  Constructing,  and  Using  Dies  for  Medals, 
Jewelry,  Coins,  and  Art  Goods. 

Workman  versus  Artist — Engraving  a  Hob  for  Sinking  a  Medal  Die 
— Chasing  Thimble,  Cane,  Whip,  and  Umbrella  Mountings — 
Making  Dies  for  Embossing  Jewelry — Modelling  Intricate  Die 
Patterns — Gelatin  Moulds — Use  of  "Modeller's  Wax" — Dies  for 
Forming  Large  Ornamental  Articles — Combination  Dies  for  Em- 
bossed Work — Making  "  Hobs  "  and  Sinking  Embossing  Dies — 
Bronze,  Brass,  and  Copper  Dies, .  468-478 


CHAPTER  XXX. 

The  Modern  Apt  of  Swaging,  Swaging-Machines  and  the  Cold- 
Swaging  Process. 

The  Hammer — Swaging  and  Hammering—The  Cold-Swaging  Proc- 
ess—Rotary Swaging-Machines — The  Dayton  Swaging-Machine 
— Horizontal  Swaging-Machines — Some  Effects  of  Work  Accom- 
plished by  Swaging, 479-491 


16  CONTENTS. 

CHAPTER  XXXI. 

Processes  and  Methods  for  the  Working  of  Aluminum. 

pages 
Aluminum  versus  Other  Metals — Difficulties  Encountered  in  Work- 
ing— Pure  Metal  versus  Alloys — Secrets  in  the  Working  of  Alu- 
minum— Grades  and  Alloys  of  Aluminum — Working  the  Metal 
— Lubricants  to  Use — Cutting  Dies  for  Aluminum — Drawing 
Dies  for  Aluminum — Drawing  Aluminum  Shells — Bending  and 
Forming  Dies  for  Aluminum — Spinning  Aluminum — Annealing 
Aluminum — Polishing  and  Finishing  Aluminum — Burnishing 
the  Metal — Engraving  and  Chasing  Aluminum — Soldering  Alu- 
minum— Aluminum  as  an  Abrasive, 492-500 

CHAPTER  XXXII. 

Hints,  Kinks,  Ways,  and  Methods  of  Use  to   Tool-Makers   and  Die- 
Makers. 

Notes  on  Circular  Forming  Tools — A  Kink  for  Drawn  Work — Brass- 
Working  Tools  and  their  Use — Grinding  Twist  Drills  for  Cut- 
ting a  Section  of  a  Hole — Truing  and  Turning  Rubber — Patent 
Tool-holders — Hard-Soldering — Speed  of  Pulleys  and  Gears — 
Etching  Steel — Boring  Long  Cast-iron  Tubes — Tinning  Castings 
— A  Handy  Die  and  Tool-maker's  Clamp — Lubricant  for  Draw- 
ing Shells — To  Glue  Leather  to  Iron — Keeping  Note-books,  501-511 

CHAPTER  XXXIII. 

The  Value  of  Up-to-date  Fixtures  and  Machine   Tools. — Conclusion. 

Lack  of  Knowledge  of  Machine  Tools — "Up-to-the-minute"  Machine 
Tools — Advantages  Gained  through  the  Use  of  Improved  Tools 
— Ideal  Twentieth-century  Manufacturing — Depreciation  in  Ma- 
chine-shops— Causes  of  Depreciation  in  Shops — The  Selection  of 
Machines  for  Manufacturing  Purposes — Universal  Equipment 
versus  Working-range  Equipment — Cause  of  the  Great  Devel- 
opment in  Machine  Tools, 512-516 


American  Tool  Making 

AND 

Interchangeable  Manufacturing 


AMERICAN  TOOL-MAKING. 


CHAPTER  I. 


The  Inception,  Development,  and  Installation  of  the 

Modern  System  of  Interchangeable 

Manufacturing. 

ELI   WHITNEY. 

The  inception  of  the  modern  system  of  interchangeable  man- 
ufacturing— according  to  the  best  authorities — was  in  1798 ;  and 
the  honor  of  being  the  first  "interchangeable  manufacturer"  be- 
longed to  Eli  Whitney,  the  inventor  of  the  cotton-gin,  who,  in 
January  of  that  year,  secured  an  order  to  furnish  the  United 
States  Government  with  ten  thousand  muskets,  four  thousand  to 
be  delivered  in  one  year  and  the  balance  in  two  years.  We  read 
that  "Mr.  Whitney  went  at  the  undertaking  in  a  very  thorough 
and  systematic  way.  First,  he  developed  a  water-power,  erected 
suitable  and  adequate  buildings,  considered  ways  and  means  for 
a  larger  and  better  product,  designed  machinery  to  effect  it,  and 
trained  workmen  to  skill  in  the  new  employment.  However,  the 
difficulties  which  he  encountered  were  greater  than  he  had  sup- 
posed, and  it  was  eight  years  instead  of  two  before  the  order  of 
ten  thousand  arms  was  completed.  Notwithstanding  this  delay, 
the  progress  of  the  enterprise  and  the  character  of  the  product  as 
delivered  was  so  satisfactory  otherwise  that  Congress  treated  him 
with  the  greatest  consideration.  His  shops  at  New  Haven,  Conn. , 
became  the  Mecca  of  government  officials,  manufacturers,  travel- 
ling notables,  and  foreigners,  and  that  which  he  could  show  was 
well  worth  a  journey,  for  his  innovations  in  the  manufacture  of 
arms  were  as  epochal  as  his  invention  of  the  cotton-gin."  It  was 
in  the  manufacture  of  those  muskets  that  Whitney  first  conceived 
and  put  into  successful  operation  "jigs"  and  "fixtures"  for  the 

19 


20  TOOL-MAKING  AND 

duplicate  production  of  parts  to  a  limited  degree  of  variation 
which  would  permit  of  their  interchanging.  Thus  the  modern 
manufacturing  system  was  born— the  system  that  not  only  revo- 
lutionized the  manufacture  of  arms,  but  became  the  basis  upon 
which  American  manufacturers  built  their  present-day  reputa- 
tion of  superiority  in  all  other  lines  of  manufactures. 

Having  gone  this  far — as  the  origin  of  the  system  has  been 
traced  and  the  inventor  given  due  credit,  as  well  as  having  j>aid 
tribute  to  his  genius — it  will  be  well  to  proceed  with  the  presen- 
tation of  the  meaning  of  "  interchangeability  "  and  the  develop- 
ment, perfecting,  and  installation  of  the  system  for  which  it 
stands. 

INTEECHANGEABILITY. 

Interchangeability  mechanically  means  to  produce  parts  in 
duplication  or  repetition,  or  the  production  of  a  part  or  piece 
which  will  fit  into  the  place  provided  for  any  other  similar  piece. 
As  a  rough  sample  of  interchangeability  we  might  take,  for  in- 
stance, the  work  of  the  brick-layer,  the  tile-setter,  or  the  mosaic- 
worker,  who  when  building  a  wall  or  blocking  a  panel  take  any 
brick,  tile,  or  cube  that  lies  nearest  to  their  work,  knowing  that 
it  will  take  up  the  same  amount  of  space  and  fit  into  place  the 
same  as  those  laid  before  it.  In  metal,  a  rough  sample  of  inter- 
changeability is  met  with  when  laying  a  line  of  water-pipe,  the 
castings  being  dropped  indiscriminately  along  the  street,  the  con- 
tractor knowing  full  well  that  one  end  of  each  will  fit  into  the 
recess  of  the  end  of  the  preceding  one. 

From  the  laying  of  bricks,  tiles,  and  water-pipe  to  the  mak- 
ing of  watches  is  quite  a  long  step ;  but  as  the  modern  watch, 
cheap  and  expensive,  represents  the  other  extreme  of  inter- 
changeability, developed  to  a  degree  almost  incomprehensible  to 
the  ordinary  mind,  it  is  a  fitting  illustration.  In  the  manufac- 
ture of  the  watch  hundreds  of  parts  go  to  make  it  up.  Take  the 
screws — the  tiny  little  things  that  one  can  hardly  see  with  the 
naked  eye ;  they  are  manufactured  by  the  million,  and  so  accu- 
rately that  the  last  one  will  fit  perfectly  into  the  tapped  hole 
provided  for  the  first  one.  The  gears,  springs,  brackets,  pinions, 
pivots,  bearings,  and  shafts  are  all  interchangeable. 


INTERCHANGEABLE  MANUFACTURING.  21 

In  referring  to  interchangeability  it  must  not  be  inferred  that 
the  system  is  only  met  with  in  the  production  of  fine  work ;  on 
the  contrary,  the  fact  is  that  the  system  is  easier  of  installation 
and  of  as  frequent  occurrence  with  rough  work. 

In  modern  manufacturing  the  first  object  sought  is  to  produce 
cheaply  and  therefore  rapidly,  and  this  object  can  only  be  at- 
tained by  producing  the  parts  or  machines  of  the  same  kind  in 
duplication.  Some  infer  that  these  modern  manufacturing 
methods  have  been  adopted  on  account  of  the  scarcity  of  skilled 
labor,  when  the  fact  is  that  it  has  been  the  great  supply  of  highly 
skilled  labor  that  has  made  the  development,  perfection,  and  in- 
stallation of  the  wonderful  system  of  interchangeable  manufac- 
turing possible.  Thus  where  years  ago  the  skill  and  ingenuity 
of  the  mechanic  were  monotonously  and  patiently  utilized  in  the 
hand  production  of  a  number  of  parts  of  great  accuracy  to  a  cer- 
tain attainable  degree  of  duplication,  they  are  now  directed  to 
the  devising  and  constructing  of  one  part  or  tool,  or  a  set  of  tools,, 
which  will  produce  other  parts  or  tools  in  endless  repetition. 
In  modern  machine  manufacturing  skill  and  ingenuity  of  an  or- 
der higher  than  were  ever  thought  possible  to  attain  have  beeu 
developed  in  the  hands  and  brains  of  the  American  tool-maker. 
And  this  skill  and  ingenuity  are  concentrated  upon  the  devising 
of  means  for  the  production  of  articles  and  parts  within  the 
slightest  possible  limits  of  variation,  and  in  which  their  complete 
interchangeability  will  be  guaranteed. 

The  man  in  whose  brain  the  modern  manufacturing  system 
was  born  was  he  that  first  took  a  piece  of  scrap-iron  and  drilled 
two  holes  in  it,  to  guide  a  drill  in  making  another  piece  with  two 
holes  in  it  the  same  distance  apart  as  in  the  first  piece.  The 
men  who  now  fill  our  drawing-rooms  and  tool-rooms  and  who  de- 
vise and  construct  tools  for  the  production  of  interchangeable 
metal  parts  are  his  descendants.  They  have  made  possible  the 
manufacture  of  the  breach-loading  gun,  the  typewriter,  the  cheap 
sewing-machine,  the  cash-register,  the  machine-made  watch,  the 
automobile,  as  well  as  a  thousand  and  one  other  mechanical  arti- 
cles, machines,  and  devices,  which  form  an  integral  part  of  our 
twentieth- century  civilization. 


22  TOOL-MAKING  AND 

INTEBCHANGEABLE  MANUFACTUBING. 

The  development  of  the  modern  system  of  manufacturing 
since  the  days  of  Eli  Whitney  has  been  simply  wonderful,  so  that 
at  the  present  time  all  machines  for  which  there  is  a  constant  or 
a  large  demand  are  or  should  be  manufactured  and  built  through 
this  system  of  interchangeability.  It  is  in  the  perfecting  of  this 
system  and  in  the  designing  and  constructing  of  tools  and  appli- 
ances for  the  successful  production  of  machinery  that  the  best 
and  brightest  men  in  the  mechanical  field  are  employed.  Take 
the  universal  milling-machine,  the  precision-lathe,  the  automatic 
screw-machine,  and  turret-lathe;  all  these  machines  are  being 
manufactured  to-day  by  a  system  which  allows  of  their  being 
constructed  and  shipped  to  any  part  of  the  world  with  their  effi- 
ciency guaranteed.  Moreover,  any  one  of  their  innumerable 
parts  can,  when  worn  out  or  broken,  be  duplicated  by  sending 
to  the  works  and  securing  the  part  needed.  This  part  can  then 
be  fastened  in  place  of  the  other  without  as  much  as  touching  it 
with  a  file,  when  it  will  perform  its  separate  and  distinct  move- 
ments as  positively  and  accurately  as  the  part  whose  place  it  has 
taken. 

"When  one  realizes  that,  in  order  for  these  machines  to  do  the 
work  expected  from  them,  each  and  every  part,  from  the  most 
minute  screw  to  the  largest  casting,  must  be  finished  to  a  degree 
of  accuracy  almost  inconceivable  to  the  lay  mind,  the  fact  that 
all  the  parts  will  interchange  with  those  on  another  machine  be- 
comes more  surprising.  Now  if  all  the  parts  of  a  modern  ma- 
chine tool  must  be  finished  so  accurately,  to  what  degree  must 
the  tools  and  appliances  used  to  produce  them  be  finished?  And 
what  of  the  men  who  have  the  skill  and  mental  capacity  neces- 
sary for  the  successful  designing  and  constructing  of  such  tools ! 

If  it  is  considered  that  twenty  years  ago  precisiommachine 
tools  of  the  present  efficiency  could  not  have  been  constructed, 
not  even  if  the  best  mechanics  available  were  employed  on  the 
work,  the  fact  that  they,  as  well  as  numberless  others,  are  now, 
and  have  been,  built  by  thousands,  becomes  more  astonishing. 

The  reason  why  such  machinery  could  not  have  been  per- 
fected and  constructed  to  accomplish  the  results  now  attained  by 


INTERCHANGEABLE  MANUFACTURING.  23 

them  was  that  there  were  not  at  that  time  tools  and  machines  of 
the  necessary  precision  and  accuracy  to  build  them,  and  it  was 
only  by  inventing  and  developing  the  use  of  such  tools  that  the 
manufacture  of  such  intricate  pieces  of  mechanism  as  the  modern 
universal  miller,  precision-lathe,  etc. ,  was  made  possible.  Nat- 
urally, in  order  to  develop  and  construct  these  tools,  the  minds 
and  hands  of  the  mechanics  had  to  be  developed,  until  to-day  the 
amount  of  brains,  skill,  and  mental  capacity  involved  in  the  de- 
signing and  constructing  of  special  machinery,  dies,  tools,  and 
fixtures  for  the  manufacturing  of  metal  parts,  articles,  appli- 
ances, and  machinery,  is  equal  to — if  not  greater  than — that 
called  into  use  in  any  of  the  other  arts  and  professions. 

This  may  seem  a  rather  strong  assertion  to  make,  but  it  is 
made  with  the  full  knowledge  of  what  it  means.  It  may  not  be 
apparent  to  all,  but  to  the  man  who  has  had  the  advantage  of 
practical  observation  and  experience  in  the  manufacturing  of 
machinery  it  is  both  right  and  just.  It  is  well  that  the  fact  is 
becoming  universally  recognized  that  men  of  the  highest  and 
rarest  attainments  are  engaged  in  the  devising  and  developing  of 
means  for  the  rapid  and  economic  production  of  machinery. 

MODERN    MANUFACTURING    OF    INTRICATE 
MACHINERY. 

As  a  practical  illustration  of  what  the  modern  system  of 
manufacturing  consists  and  how  it  is  installed  and  carried  on,  I 
will  take  up  the  various  arts  called  into  use  and  necessary  to  the 
successful  constructing  and  placing  on  the  market  of  a  machine 
for  which  there  is  a  large  demand. 

After  the  developing  and  experimenting  has  reached  a  suc- 
cessful conclusion  in  a  perfect  working  model,  the  first  thing 
necessary  is  the  designing  and  making  of  full  sets  of  wood  and 
metal  patterns,  to  be  used  for  casting  the  various  parts  which  are 
to  be  cast.  The  man  that  does  this  must  call  into  play  a  vast 
amount  of  ability  and  knowledge  in  order  to  accomplish  this  part 
of  the  work.  He  must  allow  of  all  parts  being  sufficiently 
strong,  so  that  the  castings  resulting  will  withstand  all  strain  to 
which  they  may  be  subjected  when  in  use,  and  he  must  provide 
for  giving  them,  as  far  as  possible,  a  symmetrical  and  artistic 


24  TOOJu-MAKING  AND 

appearance.  He  must  also  allow  for  shrinkage  in  the  metal 
when  cast  and  for  a  certain  amount  of  surplus  stock  at  all  points 
which  are  to  be  machined  and  finished. 

After  the  pattern-maker  has  produced  these  patterns  in  exact 
duplication  of  the  designs,  they  are  sent  to  the  foundry,  where 
the  moulder  utilizes  his  skill  and  brains,  and,  with  the  patterns 
as  models,  a  heap  of  sand  and  a  few  crude  tools  to  work  with, 
works  out  his  moulds,  from  which  a  set  of  castings  are  produced. 
This  set  is  first  machined  and  finished  by  the  use  of  the  best 
means  available,  which  calls  into  use  all  the  capacity  and  skill  of 
the  machinist.  After  all  parts  have  been  finished  and  assem- 
bled, a  finished  machine  is  the  result.  Any  defects  in  shape  or 
strength  in  the  patterns  have  now  become  apparent  in  the  fin- 
ished castings  and  the  parts.  The  patterns  are  then  carefully 
gone  over  and  these  defects  rectified,  and  another  set  cast  from 
them.  This  set  is  also  finished  and  machined,  and  then  assem- 
bled in  another  machine.  This  latter  machine  is  found  to  be  a 
great  improvement  over  the  first,  as  all  defects  and  inaccuracies 
have  been  rectified  and  each  and  every  part  has  been  machined 
as  accurately  as  possible. 

The  machine  now  goes  to  the  tool-designer,  who  is  called 
upon  to  scheme  up  and  design  complete  sets  of  tools,  dies,  fixt- 
ures, and  appliances  for  the  machining  of  all  castings  in  repeti- 
tion and  for  the  exact  duplication  of  each  and  every  other  part, 
from  the  largest  shaft  and  gear  to  the  smallest  pin  and  screw. 
To  be  capable  of  accomplishing  all  this  the  designer  must  be — 
first  of  all — a  practical  man,  familiar  with  all  mechanical  princi- 
ples necessary  to  the  successful  construction  of  the  tools,  as  well 
as  be  possessed  of  a  theoretical  knowledge  of  the  properties  of 
all  metals.  He  must  design  the  tools  to  be  both  positive  and 
accurate,  as  well  as  strong  and  durable.  He  must  also  allow  of 
their  being  constructed  as  simple  as  possible,  consistent  with  ac- 
curate production  and  rapid  handling  when  in  operation.  He 
must,  lastly,  he  certain  he  is  right  in  all  measurements  down  to 
the  smallest  fraction  of  an  inch.  In  fact,  he  must  construct  a 
perfect  set  of  tools  for  the  exact  duplication  of  all  the  parts  of 
the  machine  on  paper.  The  designer  must  also  provide  for  the 
tools  being  so  constructed  as  to  allow  of  being  handled  and  oper- 


INTERCHANGEABLE  MANUFACTURING.  25 

ated  to  their  fullest  capacity  by  men  of  the  average  skill  aud 
intelligence,  with  rapidity  and  without  the  possibility  of  error. 
By  the  time  the  designer  has  accomplished  all  this  and  gone  over 
and  verified  all  his  designs,  until  he  is  sure  of  their  accuracy  and 
of  their  coinciding  perfectly  where  necessary,  he  has  finished  his 
part  of  the  work. 

The  tool  designs  and  the  machine  now  go  to  the  tool-maker ; 
he  has  the  last,  but  not  least,  proposition  to  tackle.  Where  the 
pattern-maker  had  to  produce  his  designs  in  wood,  the  draughts- 
man his  on  paper,  and  the  moulder  his  in  sand,  the  tool-maker 
has  to  create  his  in  steel  and  iron,  which  can  neither  be  whittled 
with  a  knife,  nor  the  parts  fastened  together  with  glue,  nor  the 
mistakes  and  inaccuracies  rubbed  out  with  an  eraser.  Neither 
can  the  tool -maker  shape  his  work  in  sand  and  locate  the  points 
with  a  trowel.  He  is  the  man  on  whom  the  accuracy,  efficiency, 
and  working  qualities  of  the  finished  product  depend.  His  skill, 
ingenuity,  and  powers  of  creation  and  production  are  taxed  to 
their  fullest  extent  indeed ;  and,  unless  he  is  a  man  of  brains, 
skill,  and  experience,  all  work  of  the  designer,  pattern-maker, 
and  moulder  will  have  been  useless.  First  in  the  machining  and 
finishing  of  the  tools  and  the  placing  of  all  locating  points,  and 
then  in  the  assembling  of  the  parts,  is  his  knowledge  and  skill 
called  into  play.  As  each  tool,  fixture,  or  device  for  the  produc- 
tion of  some  special  and  distinct  part  is  finished,  it  must  be  tried 
and  proved ;  and  the  piece  machined  in  it  must  fit  exactly  in  its 
proper  position  and  coincide  perfectly  with  all  other  points  nec- 
essary in  the  other  parts,  so  that  the  performance  of  its  separate 
and  distinct  motion  will  be  guaranteed.  And  thus  on  to  the  end 
of  the  list,  until  the  full  set  of  tools  is  complete,  so  that  a  perfect 
and  complete  machine  can  be  constructed  by  their  use,  with  the 
certainty  that  all  parts  machined  in  them  will  be  found  to  inter- 
change perfectly,  so  that  they  may  be  selected  haphazard  in  the 
assembling  of  a  new  machine  or  in  the  repairing  of  an  old  one. 
When  all  the  foregoing  has  been  accomplished,  the  preliminary 
work  necessary  to  the  successful  manufacture  and  perfect  opera- 
ting of  the  machines  in  any  number  desired,  with  the  certainty 
that  each  and  every  one  will  be  an  exact  duplicate  of  the  others, 
from  the  smallest  pin  or  screw  to  the  largest  casting,  is  an  accom- 


26  TOOL-MAKING  AND 

plished  fact.  We  may  now  go  ahead  and  manufacture  by  means 
of  the  interchangeable  system,  which  allows  of  the  construction 
of  machinery  at  the  minimum  of  cost  and  to  the  maximum  of 
production ;  and,  what  is  more,  allows  of  constructing  machines 
in  exact  duplication  of  each  other,  which  could  not  be  accom- 
plished by  any  other  means. 

THE   AMERICAN   TOOL-MAKEE— THE  MOST   SKILLED 
MECHANIC   YE   THE   WOELD. 

When  all  the  skill,  capacity,  and  brains  utilized  iu  the  accom- 
plishment of  the  mechanical  results  outlined  in  the  foregoing  are 
considered,  is  it  irrelevant  to  make  the  assertion  that  the  genius 
and  intelligence  utilized  in  the  inventing,  developing,  perfecting, 
and  manufacture  of  machinery  are  second  to  none  and  above 
most  ?  We  think  not ;  and  if  any  one  who  doubts  the  truth  of  it 
will  stroll  through  a  modern  machine-shop,  of  the  kind  necessary 
to  the  production  of  intricate,  labor-saving  machinery,  and  notice 
the  various  operations  through  which  the  parts  used  in  the  con- 
struction of  such  machinery  go,  and  the  special  tools,  fixtures, 
appliances,  arrangements,  devices,  and  machinery  used  for  their 
production,  we  think  he  will  change  his  mind  and  will  be  grate- 
ful that  America  and  Americans  can  boast  of  men  who  are  capa- 
ble of  such  things ;  for  it  is  to  such  as  they,  more  than  all  others, 
that  we  owe  our  commercial  and  industrial  supremacy  of  to-day. 
The  great  changes  in  the  last  century,  which  have  contributed  to 
the  uplifting  and  betterment  of  the  human  race,  are  marked  by 
the  achievements  of  men  whose  whole  lives  and  energies  have 
been  devoted  to  the  perfection  and  production  of  things  mechan- 
ical. This  genius  of  invention  which  has  conceived,  developed, 
and  made  possible  the  manufacture  of  labor-saving  machinery, 
has  multiplied  and  improved  the  necessaries  as  well  as  the  luxu- 
ries of  life. 

We  are  known  and  acknowledged  to-day  as  the  greatest  world 
power.  What  has  made  us  so  ?  It  is  to  those  who  have  devel- 
oped and  perfected  our  modern  manufacturing  industries  that  we 
owe  the  most.  It  is  because  we  can  view  with  equanimity  the 
strivings  of  other  nations  to  outdo  us ;  because  we  can  go  out 
into  the  markets  of  the  world  and  meet  and  overcome  their  com- 


INTERCHANGEABLE  MANUFACTURING.  27 

petition,  that  we  are  what  we  are.  And  how  has  this  come 
about1?  Simply  through  the  great  inventive  ability  and  ingenu- 
ity of  American  engineers  and  mechanics.  Thus  has  the  pro- 
duction of  all  articles  and  necessaries  of  commerce  been  cheap- 
ened and  multiplied.  Go  into  the  drawing,  construction,  or  tool 
department  of  any  of  the  large  machine  establishments  and  note 
the  men  employed  therein.  They  will  be  found  to  bear  favorable 
comparison  with  those  engaged  in  any  of  the  other  arts  or  profes- 
sions. What  is  more,  these  men  do  not  stand  still,  but  keep 
increasing  their  knowledge,  and  thus  step  higher  and  higher  to 
positions  which  their  ambitious  and  capacities  entitle  them. 
From  the  ranks  of  such  men  come  the  best  of  our  inventors  of 
machinery,  our  superintendents  and  managers. 

Before  closing  this  introductory  chapter,  I  will  say  the  indus- 
trial supremacy  of  the  United  States  in  the  twentieth  century  has 
come  about  through  the  developing  and  perfecting  of  the  modern 
system  of  interchangeable  manufacturing,  and  will  ever  stand  as 
a  monument  to  the  skill  and  ingenuity  of  the  American  me- 
chanic. 


CHAPTER  II. 

Machine  Tools,  Designing,  Tool-making,  and  Tool- 
Rooms. 

MACHINE  TOOLS. 

It  has  been  well  said  that  the  foundation  of  the  industrial 
structure  of  to-day  rests  on  machine  tools ;  and  with  this  state- 
ment, I  believe,  all  who  are  familiar  with  the  mechanical  devel- 
opment of  the  last  decade  and  have  given  any  thought  to  indus- 
trial betterment  will  agree.  It  is  a  fact,  that  all  must  now 
concede,  that  without  these  machine  tools,  these  wonderful  fac- 
tors in  modern  civilization,  we  would  be  reduced  to  the  state  of 
primeval  man  and  be  forced  to  do  by  hard  physical  labor  that 
which  thousands  of  automatons  now  accomplish  for  us.  It  is  with 
machine  tools  that  all  other  machinery  is  produced ;  the  standard 
tools  of  the  universal  shop,  the  lathes,  drills,  planers,  shapers, 
millers,  boring-mills,  and  the  numerous  minor  members  of  the 
great  family,  are  all  called  upon  to  contribute  their  share  to  fur- 
ther economic  modern  manufacturing. 

Now,  in  view  of  the  afore-mentioned  facts,  it  must  be  obvi- 
ous to  all  that  the  nation  which  aims  to  lead  in  industrial  mat- 
ters must  be  the  one  that  possesses  the  most  efficient  and  best  de- 
veloped machine  tools,  as  the  possession  of  such  is  a  criterion  of 
the  mechanical  skill  and  ingenuity  of  the  country's  mechanics. 
Hence  where  the  best  machine  tools  are  found  there  will  also  be 
found  the  best  knowledge  of  how  to  operate  them  to  the  best  ad- 
vantage. Thus  we  arrive  at  the  conclusion  that  if  good  tools  are 
to  be  made,  a  comprehensive  and  broad  knowledge  of  how  tools 
should  be  used  and  the  amount  of  work  they  should  do  is  abso- 
lutely essential.  Of  those  who  are  possessed  of  this  knowledge,  it 
may  be  said  that  they  are  indeed  ornaments  to  their  profession, 
as  they  stand  equipped  to  produce  means  which  will  lighten  the 
load  bequeathed  by  Mother  Nature  to  both  man  and  beast — 
means  for  doing  the  world's  work  economically  and  efficiently. 

28 


INTERCHANGEABLE  MANUFACTURING.  29 

THE  DESIGNEE. 

When  considering  machine  tools  we  are  at  once  confronted  by 
the  fact  that  the  efficiency  of  any  machine,  device,  arrangement, 
or1  tool  used  in  manufacturing  is  determined  solely  by  the  quality 
and  quantity  of  its  output.  To  some  extent  this  is  modified  by 
the  skill  of  the  workman  using  the  machine  or  tool.  However, 
machines  and  tools  should  be  designed  and  constructed  so  that 
the  factor  of  skill  in  handling  will  be  ineffective  except  in  con- 
tributing to  produce  a  better  quality  or  a  greater  quantity  of 
work  than  is  demanded  in  the  specifications. 

Now  in  order  for  the  designer  to  be  capable  of  designing  a 
machine  or  a  tool  which  will  meet  modern  requirements,  he  must 
first  be  thoroughly  practical  and  familiar  with  the  details  of  the 
various  lines  of  manufacture  in  which  his  creation  is  to  be  em- 
ployed. A  theoretical  knowledge  of  the  properties  of  all  materi- 
als, under  all  conditions,  must  also  be  possessed  by  the  man  who 
wishes  to  accomplish  things  in  tool  design,  before  he  can  hope  to 
solve  the  innumerable  problems  which  will  confront  him.  When 
the  vast  field  to  be  covered  is  considered,  it  is  plain  to  all  that 
the  task  that  is  set  is  no  ordinary  one  and  that  his  mental  equip- 
ment must  be  very  complete  in  order  for  him  to  succeed.  It  is 
well  that  the  comparatively  limited  number  of  methods  employed 
in  the  working  of  metals  contribute  somewhat  to  the  lightening 
of  his  load.  These  methods  may  be  enumerated  as  follows: 
forging,  rolling,  pressing,  turning,  drilling,  tapping,  planing, 
milling,  grinding,  punching,  shearing,  and  sawing.  This  list 
comprises  the  most  important  methods ;  the  rest  are  minor  and 
may  be  virtually  classified  under  some  one  in  the  above-enumer- 
ated list. 

THE   GEEAT   PRINCIPLE   OF   REPRODUCTION. 

The  designing  and  constructing  of  fixtures  and  special  tools 
to  be  used  in  machine  tools  for  modern  manufacturing  represent 
the  highest  application  of  the  great  principle  of  reproduction. 
It  is  this  subject  that  we  are  about  to  take  up,  and  it  compre- 
hends not  only  the  tools  known  as  jigs  and  fixtures,  but  all  spe- 
cial tools  of  various  types  which  are  in  general  use  to-day  for  the 


30  TOOL-MAKING  AND 

cheap  and  accurate  production  of  parts  in  duplication  and  repe- 
tition, whether  of  metal  or  other  material.  The  inception  of  the 
grand  principle  may  be  traced  back  almost  to  the  beginning  of 
time. 

Perhaps  the  earliest  application  of  the  principle  of  reproduc- 
tion was  in  the  moulding  of  plastic  materials  which  were  after- 
wards baked.  From  the  days  of  the  first  use  of  moulds  to  the 
application  of  the  principle  in  the  art  of  printing  was  a  long 
step,  yet  it  was  in  that  art  that  it  next  found  use  in  printing 
from  hand  engravings  and  afterwards  from  removable  type.  Fol- 
lowing this,  the  principle  was  applied  in  the  making  of  repro- 
ductions of  paintings  and  lithographs,  in  the  coining  and  stamp- 
ing of  metals,  and  then  in  the  casting  of  metals  and  numerous 
other  materials.  In  fact,  I  might  go  on  for  pages  and  trace  the 
application  of  the  principle  of  reproduction  down  to  to-day,  and 
at  length  stop  at  a  set  of  tools  for  the  repetition  production  of  a 
modern  universal  milling-machine  or  a  precision-lathe. 

The  most  advanced  application  of  the  principle  of  reproduc- 
tion in  which  we  are  interested  is  to  be  found  in  the  use  of  tem- 
plets, gauges,  jigs,  fixtures,  and  cradles,  as  those  tools  are  chiefly 
used  in  working  and  cutting  parts  of  metal,  to  a  limited  degree 
of  variation,  which  have  been  previously  roughly  formed  by  the 
(processes  of  rolling,  drawing,  forging,  or  casting. 

FUNCTIONS   OF   JIGS   AND   FIXTUEES. 

vin\  jigs  and  fixtures  their  functions  are  often  combined  with 
those  of  machines  in  which  they  are  used,  such  as  a  machine  of 
special  design  fitted  for  operating  on  parts  of  the  same  size  and 
shape,  the  work  being  located  and  the  tools  operated  by  devices 
self  contained  in  the  machine.  This  we  find  in  a  multiple  spin- 
dle drill,  which  has  been  specially  equipped  for  drilling  all  holes 
in  a  part  of  a  machine  or  in  a  large  plate,  the  drill-spindle  cases 
being  rigidly  fixed  in  position  in  a  certain  relation  to  each  other. 
In  a  machine  of  this  type  the  position  of  the  drill  spindles  repre- 
sent the  jig,  as  it  is  only  necessary  to  place  the  work  on  the  table 
and  the  holes  may  be  drilled  in  the  same  position  as  those  in  the 
preceding  piece. 


INTERCHANGEABLE  MANXJFA CTURING. 


31 


TEMPLETS. 

Templets  are  tools  made  of  flat  pieces  of  metal,  usually 
sheet  metal,  which,  are  used  to -lay  upon  surfaces  and  are  lo- 
cated by  the  eye,  fingers,  or  fixed  flanges  or  pins,  etc. ,  so  that 
certain  edges  of  the  templet,  out- 
side or  inside,  may  be  used  as  a 
guide  for  scribing  outlines  of  them 
on  the  surfaces  of  the  work — the 
outlines  to  serve  as  guides  for  drill- 
ing holes,  cutting  grooves  below 
the  general  surface,  or  for  forming 
the  outer  or  inner  edges  of  the  part 
to  the  external  or  internal  outlines 
of  the  templet.  Thus  a  tool  of  this  kind  reproduces  marked  lines 
with  accuracy  to  a  degree  dependable  upon  the  care  taken  by  the 
user.  The  working  to  those  lines  afterwards,  however,  is  subject  to 
variable  error,  as  much  depends  upon  the  skill  of  the  workman. 

As  an  illustration,  let  us  say  that  we  make  a  templet  of  con- 
siderable thickness  and  secure  it  firmly  to  the  work,  so  as  to  allow 
of  using  the  locating  edges  for  actual  guides  for  the  cutting  tools 


Fig.  1. 


1      \ 

/    J 

)        r^           i    **>   . 

o     C 

F — '  .     (S) 

\     1 

Fig.  2. 


Fig.  3. 


— take  Figs.  1  and  2,  for  instance.  By  doing  this  we  get  the 
simplest  form  of  flat  jig.  When  the  outside  edges  of  such  a 
templet  are  used  to  locate  finished  edges  in  the  work,  the  tool 
bceomes  either  a  filing,  milling,  shaping,  or  planing  jig,  as  the 
case  may  be.  The  most  usual  use  of  a  flat  jig,  however,  is  to  lo- 
cate cylindrical  holes  of  various  sizes  and  kinds  to  be  drilled 
with  drills  or  other  similar  tools,  or  to  locate  grooves,  angles,  or 
keyways  in  parts  in  certain  relative  positions  with  other  finishing 
points.     Fig.  3  illustrates  a  die  templet. 


32 


TOOL-MAKING  AND 


GAUGES. 

In  gauges,  their  general  function  is  to  verify  standard  meas- 
urements between  points  and  locations.  While  the  use  of  such 
tools  is  well  enough  known  to  make  a  detailed  description  of  them 
superfluous,   a  few  remarks  are  essential.     Iu    accurate  work 

"  limit "  (Fig.  4)  gauges  are  frequently  - 
used.    One  gauge  represents  the  maxi- 
mum of  allowable  inaccuracy  and  the 
other  the  maximum  of  accuracy  re- 
quired — the  work  coming  within  these 
allowable  limits..    Thus  we  see  that 
the  purpose  of  gauges  is  not  so  much  to  locate  the  points  of  the 
various  finished  surfaces  in  a  piece  of  work,  as  to  inspect  them 
after  they  are  so  located. 


Fig.  4. 


FLAT   JIGS. 

In  regard  to  flat  jigs  it  may  be  said  that  the  simplest  form 
consists  usually  of  a  flat  plate  of  iron,  through  which  certain 
holes  have  been  accurately  located  and  carefully  drilled;  the  up- 
per and  lower  surfaces  of  the  plate  having  first,  of  course,  been 


=1 


oooooooooooooooo 


DOOOOOOOOOOOOOOof] 


\=J 


Fig.  5. 


Fig.  6. 


machined  true.  Thus  if  a  flat  jig  is  in  the  form  of  a  square,  or 
of  rectangular  shape,  and  of  considerable  thickness,  as  shown  in 
Fig.  5,  or,  in  other  words,  of  the  same  shape  and  size  as  the 
parts  which  are  to  be  drilled,  it  may  be  clamped  in  position  on  a 
drill-press  table  and  a  pair  of  parallels  used  to  set  against  two 
of  its  edges,  the  parallels  being  set  at  right  angles  to  each  other 
and  clamped  when  the  drill  has  been  set  to  enter  one  of  the  holes 
to  the  depth  required,  or  all  the  way  through,  whichever  may  be 
the  case.     After  this  has  been  done  the  model  or  flat  jig  may  be 


INTERCHANGEABLE  MANUFACTURING.  33 

removed  and  the  parts  drilled  in  exact  duplication  of  it  by  setting 
them  against  the  parallels  and  clamping  them  and  then  drilling. 
Then  again  the  fiat  jig  may  be  made  to  fit  the  top  of  the  work 
and  the  holes  drilled  by  guiding  the  drill  through  those  in  the  jig. 
A  type  of  fiat  jig  most  generally  used  is  shown  in  Fig.  7. 
They  are  usually  equipped  with  downward  projecting  lugs  or 
pins,  which  are  used  to  locate  the  jig  on  the  work,  thus  obviating 
the  necessity  of  depending  on  the  hand  or  fingers  of  the  operator 
for  the  locating.  Very  often  devices,  such  as  screws,  clamps,  or 
other  fasteners,  are  contained  in  the  jig  (Fig.  8),  being  located 


Fig.  7.  Fig.  8. 

upon  one  or  more  sides  of  the  jig,  the  same  serving  to  pull  the 
jig  in  one  or  two  directions  against  the  work.  Where  the  work 
varies  in  size  or  shape,  such  as  in  castings,  the  clamping  is  usu- 
ally central  and  made  to  operate  in  all  directions,  so  as  to  com- 
pensate for  the  degree  of  variation  in  the  castings. 


s 


BOX-JIGS. 


In  the  further  development  of  the  reproducing  principle,  we 
come  to  the  box-jig.  This  type  of  jig  stands  upon  its  own  bottom 
when  in  use,  the  work  being  dropped  into  it  and  located  by  suit- 
able means  against  stops  and  down  on  bosses  on  the  sides  of  the 
jig  and  on  the  inner  surface  of  its  bottom.  A  jig  of  this  kind  is 
usually  equipped  with  a  lid  in  which  the  bushings  for  guiding 
the  drills  are  located.  Very  often  the  work  is  located  and  fast- 
ened within  such  jigs  by  merely  dropping  the  lid  down  and  fast- 
ening it.  When  all  holes  to  be  drilled  in  a  box-jig  are  to  be  par- 
allel to  each  other,  the  jig  always  stands  upon  its  bottom  while 
in  use ;  but  when  holes  are  to  be  drilled  at  right  angles,  from  the 
top  and  sides  or  from  any  of  the  six  sides  of  the  jig,  it  is  neces- 
sary that  all  opposite  sides  from  which  drilling  is  to  be  done 

A.  T.— 3 


34  TOOL-MAKING  AND 

should  be  provided  with  surfaces  for  resting  the  jig  on  the  table. 
These  resting  surfaces  or  "bottoms"  may  be  at  any  desired  angle 
to  each  other,  may  be  cast  with  the  jig  body  and  machined  and 
squared,  or  be  of  steel  and  screwed  or  forced  in. 

Box- jigs  of  the  most  common  types  are  frequently  used  for 
drilling  all  holes  in  frames  of  small  machines,  standards,  or  other 
similar  parts.  The  work  is  put  into  the  jig  and  located  by  cer- 
tain surfaces  which  are  most  favorable  for  producing  uniformity. 
After  the  work  is  located  the  jig  is  placed  on  the  table  of  a  gang 
drill  and  all  holes  finished  as  desired ;  drilling,  counter-boring, 
boring,  or  reaming,  as  may  be  desired,  each  spindle  of  the  drill 
being  equipped  with  the  proper  tools  to  accomplish  the  opera- 
tion required.  Thus  by  the  use  of  such  jigs  unskilled  labor  may 
be  employed  for  drilling  any  number  of  accurately  spaced  holes 
in  thousands  of  pieces,  with  the  certainty  that  interchangeability 
will  be  assured.  As  the  jig  may  be  constructed  so  as  to  be  easy 
to  manipulate  while  sliding  it  from  one  spindle  to  another  or 
turning  it  on  its  different  sides,  the  physical  exertion  required  of 
the  operator  is  not  great ;  therefore  the  work  is  accomplished 
accurately  with  ease  mentally  and  physically. 

Again,  we  will  often  find  the  box-jig  in  simpler  form,  the 
general  shape  being  fiat  with  a  number  of  lugs  or  legs  projecting 
downward.  With  a  jig  of  this  sort  the' lower  surface  of  the  lugs 
serve  as  legs,  the  work  being  clamped  up  against  the  lower  sur- 
face of  the  jig  body.  Then,  again,  there  is  still  another  type, 
which  might  properly  be  called  a  "skeleton"  jig,  from  the  fact 
that  it  is  merely  a  light  skeleton  frame  in  form.  It  is  for  very 
heavy  work  that  these  skeleton  jigs  are  used,  weight  being  a  con- 
siderable factor,  and  in  order  for  the  operator  to  be  able  to  han- 
dle the  combined  jig  and  work  without  undue  exertion  the  jig 
must  be  made  as  light  as  possible. 

WOEK  THAT  SHOULD   NOT    BE    JIGGED— JIGS   FOB 
HEAVY    WOEK. 

While  most  machine  work  can  be  "jigged"  to  advantage, 
there  is  some  that  it  would  be  obviously  impracticable  to  handle 
in  this  way;  such  as  machine  bases  of  large  size,  lathe  beds, 
large  press  frames,  etc.     On  the  contrary,  it  is  always  well  to 


INTERCHANGEABLE  MANUFACTURING.  35 

continue  doing  all  necessary  work  on  such  parts,  such  as  turning, 
planing,  and  milling,  by  the  ordinary  methods ;  using  templets 
and  gauges  for  locating  the  finished  surfaces,  and  then  afterwards 
using  small  local  jigs  or  templets  for  locating  necessary  holes 
from  some  of  the  already  finished  surfaces.  When  jigs  are  used 
for  such  work  they  should  be  made  for  locating  only  one  hole  or 
for  locating  two  or  a  number  of  them  which  are  to  be  placed 
close  together.  When  such  jigs  are  made  small  enough,  they 
may  be  handled  with  ease  and  located  in  succession  on  various 
parts  of  the  work. 

"While  the  saving  of  weight  is  very  important  in  making  large 
jigs  in  order  to  allow  of  their  easy  handling,  it  must  not  be  car- 
ried too  far.  It  is  absolutely  necessary  in  jigs  for  heavy  work 
that  lightness  be  combined  with  stiffness,  and  this  can  only  be 
brought  about  through  careful  designing.  Very  often  large  jigs 
have  been  carefully  made  which,  wheu  fastened  to  the  work, 
would  bend  or  twist,  thus  throwing  the  holes  and  locating  points 
out  of  place,  the  cause  being  inattention  on  the  part  of  the  de- 
signer to  the  factor  of  stiffness. 

For  the  frames  of  large  jigs  it  will  usually  be  found  best  to 
use  cast  iron,  as  with  this  metal  the  working  parts  will  maintain 
their  position  without  warping  or  bending;  in  fact,  they  will 
remain  positive  until  a  sufficient  strain  has  been  brought  to  bear 
on  them  to  crack  them.  When  bodies  of  such  jigs  are  made  of 
steel  castings,  forgings,  or  brass,  they  often  become  inaccurate, 
and  these  defects  are  not  usually  discovered  until  a  large  quantity 
of  valuable  work  has  been  spoiled  by  their  use. 

CHEAP   JIGS. 

For  small  quantities  of  work  cheap  jigs  are  sometimes  used. 
They  are  made  by  simply  drilling  the  working  holes  through  the 
body  of  the  cast  iron  or  steel  plate  of  which  they  are  made.  Of 
course,  jigs  of  this  construction  are  not  very  durable,  as  the 
drills  wear  the  holes  and  the  alignment  is  not  maintained. 
Then,  again,  such  jigs  are  made  by  fastening  a  hardened  steel 
plate  in  which  the  proper  working  holes  have  been  drilled  to  the 
frame  of  the  jig.  However,  the  use  of  hardened  steel  plates  for 
the  purpose  designed  is  somewhat  interdicted  by  the  warping  of 


36 


TOOL-MAKING  AND 


the  steel  in  hardening,  thus  destroying  the  alignment  and  displac- 
ing the  holes  in  their  relation  to  each  other. 

ACCURATE   JIGS. 

When  large  quantities  of  accurate  work  are  to  be  done  in 
jigs,  the  tools,  of  course,  should  be  carefully  made.  In  such  jigs 
drill  guiding  holes   should    always  be  bushed  with  hardened, 


pig.  9. 

lapped,  and  ground  steel  bushings,  made  to  standard  external 
diameters,  so  that  they  may  be  easily  replaced  when  the  inside 
has  been  worn  by  the  revolving  of  the  drills  while  working. 
Such  bushings  are  usually  forced  tightly  into  reamed  holes  in  the 
jig  bodies.  For  producing  accurate  work  in  small  quantities 
interchangeable  bushings  are  used,  a  full  set  of  them  being  kept 
on  hand.  These  bushings  may  be  used  in  any  of  the  large  jigs  in 
the  shop  indiscriminately. 


TOOL-BOOMS   AXD   THEIR   EQUIPMENT. 


Katurally,  in  a  chapter  devoted  to  the  value  of  tools  and  the 
evolution  and  development  of  tool -making,  one  expects  to  find 


INTERCHANGEABLE  MANUFA  CTTJRING. 


37 


something  on  tool-rooms ;   at  all  events,  a  few  remarks  on  the 
subject  will  be  timely. 

Tool -rooms  are  of  two  classes — those  in  which  tools  and  fixt- 
ures are  made  and  those  in  which  they  are  kept.  In  those  of 
the  first  class  the  most  important  item  is  the  lathe.  An  approved 
type  of  a  modern  tool-maker's  lathe  is  shown  in  Figs.  9  and  10, 


Fig.  10. 

the  general  features  of  which  are  apparent.  It  is  a  ten-inch, 
tool-maker's  lathe,  and  its  design  and  construction  represent  the 
attainment  of  perfect  and  complete  convenience.  It  is  one  of  the 
most  complete  precision-lathes  ever  produced  for  the  tool-maker 
or  model-maker.  Now,  of  all  machine  tools,  for  either  tool-mak- 
ing or  manufacturing,  the  lathe  is  king.  If  a  machine-shop  or  a 
tool-room  is  to  have  only  one  tool  in  it,  it  is  obvious  to  all  that 
the  tool  should  be  a  lathe,  and  it  should  be  a  good  lathe.  With 
a  good  lathe  and  a  skilled  mechanic  to  operate  it  and  bring  out 
all  its  capabilities,  almost  anything  in  the  line  of  tool-making 
and  machine  construction  may  be  accomplished.  As  to-day  lathes 


38  TOOL-MAKING   AND 

are  being  built  in  the  most  astonishing  variety  of  capacities,  from 
the  delicate  precision-lathe  to  the  ponderous  three-hundred  tons 
gun-lathe,  no  difficulties  should  be  experienced  in  procuring  one 
for  any  special  line  of  tool-making  or  manufacturing. 

After  the  lathe,  next  in  importance  comes  the  drill-press,  the 
selection  of  which  depends  upon  the  class  of  work  to  be  done. 
Usually  there  should  be  two — a  small  sensitive  drill  and  a  large 
column  machine.  Next  we  have  the  universal  milling-machine, 
with  its  boundless  possibilities.  In  order  of  importance  the 
shaper  and  planer  come  next,  and  in  their  choice  the  nature  of 
the  work  to  be  done  is  also  the  chief  factor  to  be  considered. 
Vises  and  small  tools,  of  course,  follow;  then  the  speed-lathe, 
for  hand-tooling,  polishing,  and  lapping.  Lastly,  the  modern 
tool-room  is  not  complete  without  a  tool-grinder.  All  of  these 
machines  are  sufficiently  well  known  and  a  detailed  description 
of  any  would  only  take  up  valuable  space. 

In  regard  to  a  tool-room  of  the  second  class,  it  must  be  obvi- 
ous to  all  that  its  chief  requisites  are  that  it  shall  form  a  conven- 
ient place  where  tools  and  appliances  may  be  systematically 
and  handily  distributed.  In  a  small  establishment  only  one  tool- 
room is  necessary,  but  in  any  extensive  establishment,  where 
there  are  several  buildings  and  several  floors  in  each  building,  it 
is  necessary  that  there  shall  be  a  number  of  tool-rooms  in  order 
that  there  shall  be  convenience  in  the  distribution  of  the  tools. 

In  order  that  the  reader  may  understand  what  a  tool-room 
should  be  like,  it  is  essential  that  a  short  description  of  a  model 
one  should  be  presented.  I  know  of  no  better  way  of  doing  this 
than  by  describing  those  in  the  shops  of  Brown  &  Skarpe,  Provi- 
dence, E.  I.,  U.  S.  A.  In  their  shops  the  different  tool-rooms 
are  much  alike,  the  largest  one  being  on  the  second  floor  of  the 
main  building,  where  all  lathe  tools  are  ground  on  a  Seller's 
grinder  before  being  given  out,  and  other  work  of  like  character 
done.  Like  all  shops  in  which  large  numbers  and  varieties  of 
tools  are  in  use,  the  check  system  is  in  use.  Ten  checks  are  giv- 
en each  workman,  one  of  which  is  placed  opposite  the  place  re- 
served for  any  tool  that  he  has  out.  One  noticeable  and  excel- 
lent feature  of  these  tool-rooms  is  the  good  supply  of  parallels  in 
each.     To  save  checks,  when  a  workman  requires  several  paral- 


INTERCHANGEABLE  MANUFA  CTUBING. 


39 


lels  the  system  shown  in  Fig.  11  is  in  use.  The  parallels  are  placed 
in  pigeon-holes,  those  of  one  size  in  one  row,  the  next  larger  in  a 
row  below,  and  so  on.  At  the  right  is  a  board,  on  the  side  of 
which  is  marked  the  size  of  the  parallels  in  each  row,  and  at  the 
top  of  which  are  the  numbers  1  to  6,  to  indicate  the  number  of 
parallels  in  use.  Checks  in  the  positions  shown  would  indicate  that 
a  workman  had  out  four  1^-inch  parallels  and  three  2f-inch  ones. 
In  a  great  many  shops  it  is  common  to  keep  the  tool -rooms 
supplied  with  sets  of  taps  and  tap-drills  together  in  two  blocks, 


13      3     4      5     6 

iyJL 0 

w/s"             -0,    . 

ate. 

rn 

i — i 

i  i 

i — i 

i — i 

i  i 

1      1 

rn 

i  i 

i  i 

i  i 

i  i 

1      I 

I    I 

i   i 

i   i 

i   i 

i   i 

rn 

'rn 

rn 

rn 

i    i 

i    i 

1 

1 

3x3" 

m?—    O 

m 

rn 

rn 

rn 

rn 

m 

FIG.  11. 

only  one  check  being  necessary  to  secure  the  whole.  In  the 
Brown  &  Sharpe  tool-rooms  the  tap  blocks  are  more  completely 
equipped  than  usual.  Each  set  or  block  consists  of  a  full  set  of 
drill,  tap-drill,  starting,  sizing,  and  bottom -tap,  two  counter- bores 
for  holes  where  countersunk  head-screws  are  used,  one  counter- 
bore  having  a  tip  the  size  of  a  standard  hole  and  the  other  to  fit 
a  tap-drill  hole ;  each  block  also  contains  a  test  plug,  giving  the 
size  of  a  standard  head  for  screws  of  that  size  and  a  tap-wrench. 
In  regard  to  keeping  track  of  workmen's  supplies,  there  is  a 
novel  system  in  use.  It  consists  of  a  six-sided  case,  one  in  each 
tool-room,  on  the  sides  of  which  hang  an  extra  size  of  ten  checks 
for  each  man.  The  top  of  the  case  is  divided  into  several  com- 
partments, marked,  respectively,  "Oil,"  "Waste,"  "Towels," 
"Emery  Cloth,"  etc.,  and  when  a  man  wants  a  ball  of  waste  one 
of  his  checks  is  dropped  into  the  receptacle  bearing  this  name. 
Thus  after  a  certain  time  has  elapsed  the  checks  may  be  removed, 
counted,  and  a  record  taken  of  the  amount  of  supplies  which  each 
man  has  used.     The  checks  are  then  put  back  on  their  pins. 


CHAPTER  III. 

Fundamental  Principles,  Proeessses  and  Practical 
Points  for  Jig  Design  and  Construction. 

Before  taking  up  the  various  types  of  jigs  and  fixtures  used 
for  the  production  of  repetition  parts  by  drilling  and  milling, 
and  illustrating  them  and  describing  their  construction  and  use 
in  detail,  I  have  thought  best  to  devote  a  chapter  to  a  presenta- 
tion of  the  fundamental  principles,  various  processes,  and  prac- 
tical points  which  are  required  to  be  understood  in  order  to  suc- 
cessfully design  and  construct  drilling  jigs  and  fixtures  or 
similar  special  tools  used  for  the  machining  and  duplication  of 
machine  parts.  If  the  rules  laid  down  are  followed,  much  un- 
necessary labor  and  expense  will  be  avoided  and  the  best  of 
results  attained.  The  descriptions  are  given  from  an  entirely 
practical  point  of  view,  the  theoretical  not  being  touched  upon 
and  anything  purely  speculative  being  omitted. 

FACTOKS   INVOLVED. 

In  the  first  place,  let  it  be  understood  that  there  is  no  one 
other  branch  of  the  machine  business  that  requires  more  thought, 
wider  knowledge,  and  broader  experience  of  shop  conditions  than 
the  designing  of  jigs  and  fixtures,  and  in  order  for  one  to  be 
competent  to  do  this  work  successfully  he  must  xDossess  this  essen- 
tial knowledge  of  shop  conditions.  To  those  who  are  not  so 
equipped  a  close  study  of  the  chief  factors  and  the  fundamental 
principles  involved  will  be  of  untold  value. 

In  jig  and  fixture  work  there  are  six  highly  important  factors 
to  be  considered:  1.  The  course  the  work  is  to  follow  during 
manufacture.  2.  The  locating  and  securing  of  the  work  in  the 
fixtures.  3.  Keeping  of  the  locating  points  for  the  work  free 
from  chips  and  dirt.  4.  Self-contained  tools.  5.  The  class  of 
help  that  will  use  the  tools.  6.  Convenience  and  ease  in  hand- 
ling the  tools  during  their  operation. 

40 


INTERCHANGEABLE  MANUFACTURING.  41 

Taking  the  first  factor — the  course  of  the  work  during  manu- 
facture— we  will  say  that  a  part  of  a  machine  is  given  us  to  design 
tools  for  its  production  in  repetition.  Now  say  that  the  part,  in 
order  to  complete  it,  will  have  to  go  through  two  operations, 
drilling  and  milling.  The  question  is  which  should  be  done 
first,  the  drilling  or  the  milling? 

In  most  cases  where  the  part  is  to  be  drilled  and  milled,  it  is 
best  to  provide  for  doing  the  milling  first ;  because  it  is  desirable 
that  the  drilled  holes  and  milled  surfaces  shall  bear  a  certain 
definite  relation  to  each  other,  and  because  by  having  the  holes 
drilled  from  a  milled  surface  greater  accuracy  and  interchange- 
ability  in  the  parts  can  be  obtained  than  if  the  milling  were  at- 
tempted after  the  drilling  of  the  holes.  However,  in  order  to 
decide  the  question,  a  u working  point  or  surface"  must  be  de- 
cided upon.  Whether  the  part  to  be  machined  is  a  casting  or 
not,  there  is  always  one  point  which  from  its  position — that  is,  in 
relation  to  others— should  be  taken  as  a  "working  point,"  a  point 
to  work  froni  and  refer  to  in  all  subsequent  operations  required 
to  manufacture  the  particular  part.  The  point  chosen  may  be  a 
hole,  a  plain  surface,  a  slot,  or  a  lug  or  a  boss — it  matters  not. 

THE   LOCATING   AND    HOLDING  DEVICES. 

Now  having  chosen  the  working  point,  it  follows  that  this  is 
the  point  to  be  machined  first,  and  that  the  first  jig  or  fixture  to 
be  made  is  the  one  for  this  operation.  This  is  the  secret  of  suc- 
cessful jig-making.  Also  use  this  point  for  the  locating  of  the 
work  in  the  different  jigs  and  fixtures  for  subsequent  operations. 
Never  change  a  working  point,  as  the  performing  of  one  opera- 
tion from  one  point  and  the  next  from  another  is  not  conducive 
to  good  results. 

When  designing  fixtures  for  drop-forgings,  turned  work, 
punch-blanks,  or  any  part  that  has  been  previously  put  through 
a  cutting,  abrading,  compressing,  or  forming  operation,  the  con- 
tour of  the  part  is  usually  such  that  the  holding  of  it  is  a  simple 
matter,  especially  if  the  first  operation  is  to  be  a  milling  cut. 
With  castings,  however,  through  their  lack  of  uniformity  in 
many  cases,  fixtures  of  intricate  and  costly  design  are  required, 
thus  necessitating  considerable  care  and  judgment  in  the  devising 


42  TOOL-MAKING  AND 

of  the  locating  and  holding  means.  If,  instead  of  milling,  it  is 
decided  that  the  drilling  should  be  done  first,  and  that  the  holes 
so  produced  are  to  be  used  in  locating  and  securing  the  work  in- 
stead of  using  the  outline,  it  will  be  found  that  a  simpler  and  less 
costly  fixture  can  be  used.  Whichever  course  is  decided  upon, 
the  fixtures  should  be  so  designed  as  to  allow  of  all  operations  of 
one  class  being  completed  before  commencing  on  another  class. 

Now  in  regard  to  locating  and  securing  the  work  quickly,  ac- 
curately, and  easily,  these  are  factors  of  the  greatest  importance, 
and  it  is  difficult  to  discuss  them  properly,  for  the  efficiency  of 
the  finished  work  depends  more  than  anything  else  upon  them. 

The  various  methods  in  universal  use  for  locating  and  fasten- 
ing the  work  to  be  machined  in  jigs  and  fixtures,  such  as  bunters, 
cams,  set  screws,  spring  pins,  slides,  flat  taper  pins,  etc.,  are  well 
known,  and  I  will  not  attempt  to  lay  down  a  general  rule  for 
their  application,  as  this  must  be  decided  by  the  designer  accord- 
ing to  the  type  of  fixture  and  the  nature  of  the  work. 

One  of  the  most  essential  conditions  necessary  to  the  accurate 
and  rapid  production  of  work  in  jigs  and  fixtures  is  convenience  in 
keeping  the  locating  point  free  from  dirt.  This  must  be  evident 
to  any  one  at  all  familiar  with  the  use  and  object  of  such  tools. 

When  I  state  that  tools  should  be  self-contained,  I  mean  that 
all  devices  and  means  utilized  in  the  locating  and  securing  of  the 
work  should  be  component  parts  of  the  tool.  When  this  is  the 
case,  the  operator  is  not  obliged  to  use  a  hammer,  wrench,  or 
any  other  tool  in  order  to  operate  the  fixture. 

SIMPLE  DRILLING -JIGS. 

When  drill-jigs  of  the  comparatively  simple  types  are  to  be 
constructed  for  the  machining  of  parts  in  which  no  great  accu- 
racy is  required,  the  main  point  to  be  considered  is  the  inter- 
changeability  required  in  the  work  after  it  is  machined.  With 
this  point  constantly  in  mind,  the  avoiding  of  all  unnecessary 
expense  and  labor  will  not  be  difficult.  In  the  construction  of 
simple  jigs,  which  are  to  be  used  for  the  drilling  of  parts  which 
have  been  first  finished  at  one  or  more  points,  or  for  rough  cast- 
ings which  have  not  had  any  previous  machining,  the  most  essen- 
tial points  necessary  to  their  successful  construction  and  use  are 


INTERCHANGEABLE  MANUFACTURING.  43 

as  follows :  First,  in  making  the  patterns  construct  them  so  as  to 
leave  openings  in  the  castings  at  all  points  wherever  possible, 
without  affecting  the  strength  or  rigidity  of  the  castings  when 
finished,  for  the  escape  of  the  chips  and  dirt.  Second,  provide 
spots  with  j  ust  surface  enough  to  allow  of  their  rapid  surfacing. 
Lastly,  so  design  the  jig  as  to  allow  of  the  expeditious  fastening 
and  locating  of  the  work  and  its  removal  when  finished,  as  this 
is  one  of  the  important  factors  in  the  operation  of  such  tools. 

CONSTBUCTING   SIMPLE   JIGS. 

When  constructing,  after  having  done  the  preliminary  ma- 
chining of  all  necessary  outside  points,  choose  the  most  reliable 
and  positive  points  for  locating  the  work.  First,  a  machined 
surface  for  the  positive  points  for  locating.  When  this  is  not 
possible,  those  points  in  which  the  minimum  of  variation  is  to  be 
expected  in  the  castings  should  be  chosen.  Then,  in  the  fasten- 
ing of  the  work  within  the  jig,  use  means  which  will  be  the 
quickest  in  operation  consistent  with  all  possible  simplicity. 
As  there  are  any  number  of  simple  and  inexpensive  devices  which 
can  be  adopted  to  allow  this,  it  should  not  be  difficult. 

One  point  which  cannot  be  too  strongly  impressed  on  the  de- 
signer of  simple  jigs  is  to  allow  excess  of  metal  at  as  few  j>oints 
as  possible ;  that  is,  only  at  the  locating  and  squaring  surfaces. 
The  all  too  prevalent  habit  of  leaving  unnecessary  surfaces  to  be 
finished  is  expensive  and  not  consistent  with  satisfactory  results. 

PEOCESSES   OF   ACCURATE   JIG-MAKING. 


When  drill-jigs  are  to  be  made  for  the  drilling  of  work  in 
which  the  utmost  accuracy  is  desired,  the  locating  and  finishing 
of  the  bushing-holes  is  of  the  greatest  importance,  and  for  that 
reason  I  give  here  descriptions  of  the  most  rapid  and  practical 
methods  for  the  accomplishment  of  this  part  of  the  work. 

THE  BUTTON   METHOD   FOE   LOCATING   DEILL 
BUSHING-HOLES. 

In  the  first  place,  if  the  jig  to  be  made  is  of  the  box  type — 
which  is  the  most  generally  used  type — for  which  the  body  cast- 
ing has  been  secured,  after  all  sides  and  bearing  surfaces  have 


44 


TOOL-MAKING   AND 


been  planed  or  milled  square  and  true  with  each  other,  including 
the  feet,  it  should  be  rested  on  a  surface  plate,  as  shown  in  Fig. 
12,  which  should  be  used  only  for  work  of  this  class.  If  the  feet 
are  cast  on  the  jig,  they  should  be  scraped  until  the  sides  of  the 


S 


2^ 


SURFACE  PLATE 


FIG.  12. 

body  portion  are  at  perfect  right  angles  with  their  bottoms  and 
until  all  legs  rest  perfectly  square  on  the  surface  plate.  If  the 
feet  are  of  tool  steel  and  are  screwed  into  the  jig,  they  should  be 
hardened  and  lapped  on  a  flat  lapping-plate  (as  shown  in  Fig. 
13),  until  the  same  results  are  accomplished.     This  preliminary 


Fig.  13. 


work  on  the  jig  is  the  basis  for  the  successful  attaining  of  all 
other  results,  and  unless  done  carefully  there  is  no  possibility  of 
the  remainder  of  the  work  being  accomplished  accurately. 

For  the  laying  out  or  locating  of  the  bushing-holes  in  jigs,  and 


INTEBGEANGEABLE  MANTJFA  GT TJBING. 


45 


the  finishing  of  them,  there  are  any  number  of  methods  in  use 
among  tool- makers.  Some  of  these  methods  allow  of  fair  results 
being  attained,  while  others  are  useless,  and  when  accurate  or 
satisfactory  results  are  accomplished  though  their  use  it  is  pure 
luck,  not  the  method  that  does  it.  There  is  only  one  method  for 
locating  bushing-holes  in  small  and  medium-sized  jigs  accurately 
and  expeditiously. 

The  following  method  is  used  by  the  best  tool -makers  on  this 
class  of  work  and  is  known  as  the  "button  method":  In  shops 
where  jigs  for  accurate  production  are  constructed,  a  few  sets  of 
locating  buttons  should  be  kept  in  the  tool-room  as  standard 
sizes — say,  five-sixteenths,  one-half,  and  three-fourths  inch  in 
diameter,  as  shown  in  Fig.  14.  They  should  be  of  tool-steel  and 
finished  to  from  one-half  to  one  inch  in  length,  and  should  have 


Fastening  Screw 


Countersunk  End 


Fig.  14. 


a  hole  through  them  large  enough  to  allow  about  three-sixty- 
fourths  inch  clearance  for  the  fastening  screws,  after  which  they 
should  be  hardened  and  then  ground  perfectly  square  on  each 
end,  and  on  the  outside  to  standard  size,  finally  lapping  them  to 
get  them  accurate.  One  end  of  the  button  should  be  slightly 
countersunk,  so  that  it  will  rest  squarely  on  the  jig  when  in  posi- 
tion. The  centres  for  the  bushing-holes  in  the  jig  should  next  be 
located  approximately  correct  by  the  dividers  and  then  prick- 
punched.  They  should  then  be  drilled  and  tapped  for  the  button 
screws. 

To  locate  the  holes  positively,  first  secure  a  button  in  position 
by  working  from  two  sides  of  the  jig,  using  a  Brown  &  Sharpe 
height-gauge,  and  fasten  it  securely  by  tightening  the  button 
screw.  Locate  the  next  hole  in  the  same  manner,  using  the  height 
gauge  or  vernier  gauge  to  get  the  buttons  exactly  the  proper  dis- 


46 


TOOL-MAKING  AND 


tance  apart  and.  from  the  sides  of  the  jig,  the  hole  in  the  buttons 
being  sufficiently  large  to  allow  of  adjusting  them  in  any  direc- 
tion. After  having  set  the  buttons  to  the  number  of  holes  re- 
quired, and  having  fastened  them  securely,  as  shown  in  Fig.  15, 


Fig.  15. 


the  finishing  of  the  holes  is  in  order.  This  may  be  accomplished 
by  strapping  or  clamping  the  jig  body  or  lid,  as  the  case  may 
require,  on  the  lathe  face-plate,  being  careful  not  to  spring  it, 
and  then  truing  the  first  button  by  the  use  of  a  centre  indicator 
or  "wiggler,"  as  shown  in  Fig.  16.     The  button  should  then  be 


Fig.  16. 

removed  and  the  hole  bored  and  reamed  to  the  finish  size.  Then 
shift  the  jig,  locate  the  next  button  perfectly  true,  and  repeat 
the  boring  and  reaming  operations ;  and  proceed  in  this  manner 
until  all  the  holes  required  have  been  finished.     By  the  use  of 


INTERCHANGEABLE  MANUFACTURING.  47 

this  method  jigs  of  the  greatest  accuracy  can  be  successfully  con- 
structed without  trouble  and  worry  on  the  part  of  the  tool -maker, 
and  the  results  in  the  castings  to  be  machined  in  them  will  be  a 
foregone  conclusion. 

PATTERNS   FOE   CASTINGS  TO   BE  JIGGED. 

In  order  to  produce  good  work  from  intricate  jigs,  it  is  abso- 
lutely necessary  that  the  castings  to  be  drilled  in  them  should  be 
of  uniform  size  and  shape.  To  insure  this,  the  patterns  from 
which  they  are  cast  should  be  of  metal  in  all  cases,  finished  at  all 
points  to  the  size  required ;  allowing,  of  course,  for  shrinkage 
and  surplus  stock  at  all  points  which  are  to  be  machined  pre- 
vious to  drilling.  'When  perfect  patterns  are  made  there  will  be 
no  doubt  as  to  the  results  in  the  castings. 

If  the  method  described  in  the  foregoing  for  the  locating  and 
finishing  of  the  bushing-holes  in  small  jigs  of  the  accurate  types 
were  more  generally  known  and  used  by  tool-makers,  there 
would  be  less  worry  in  the  accomplishment  of  successful  results 
than  is  at  present  experienced  in  the  effort  to  obtain  the  same  by 
methods  which  are  now  obsolete. 

Besides  the  locating  and  finishing  of  the  bushing-holes  in  the 
most  accurate  manner,  the  following  must  be  kept  in  mind  in 
order  that  satisfactory  results  will  be  attained  in  jig-making. 
All  the  various  parts  of  such  jigs,  including  the  body  castings, 
should  be  made  sufficiently  heavy  and  strong  to  withstand  all 
strain  to  which  they  may  be  subjected  when  in  use.  The  man- 
ner of  locating  the  work  within  the  jigs  should  be  such  as  to  be 
positive  and  to  eliminate  the  possibility  of  shifting  during  the 
operation  of  the  tools.  For  instance,  it  would  be  ridiculous  to 
adopt  a  device  of  the  same  strength  for  fastening  a  piece  in 
which  a  one -inch  hole  is  to  be  drilled  as  would  be  used  for  hold- 
ing a  piece  in  which  a  one-half -inch  hole  is  required.  The  means 
and  points  chosen  for  the  fastening  of  the  work  within  the  jigs 
and  against  the  locating  points  should  be  such  as  to  allow  of 
rapid  manipulation  and  in  no  way  to  interfere  with  the  drilling ; 
and,  lastly,  the  design  and  construction  of  the  tools  should  be 
such  as  to  dispense  with  all  unnecessary  parts  and  labor. 


48 


TOOL-MAKING   AND 


LOCATING   AND    FINISHING    DRILL   BUSHING-HOLES 
IN   LAEGE   JIGS. 

The  following  method  of  locating  and  finishing  bushing-holes 
pertains  to  large  jigs.  As  a  rule,  the  castings  of  large  jigs  for 
machining  heavy  parts  are  of  considerable  size  and  weight.  It  is 
not  always  possible  to  swing  them  on  the  lathe  face-plate  and  fin- 
ish the  bushing-holes  by  the  "button"  method;  as  the  cumber- 


VERTICAL 
ATTACH MEN 


FIG.  1? 


some  shape  and  unusual  size  of  the  body  castings  interdict  the 
accurate  and  positive  locating  of  the  buttons  and  make  the  task 
wellnigh  impossible,  we  are  forced  to  adopt  other  means  which 


INTERCHANGEABLE  MANUFA CTURING. 


49 


will  allow  of  accomplishing  the  result  in  an  easy  manner.  To  do 
this  we  use  a  universal  milling-machine  which  is  equipped  with 
a  vertical  attachment.     First,  we  strap  the  jig  body  on  the  table 


Fig.  18. 

and  then  locate  the  holes  by  using  the  cross  and  longitudinal  feed- 
screw graduations,  the  vertical  feed,  a  pair  of  twelve-inch  ver- 
niers, and  a  B.  &  S.  height-gauge.  The  actual  work  is  accom- 
plished by  first  locating  and  finishing  the  holes  in  the  upper 
surface  of  the  jig  body,  using  a  small  drill-chuck,  as  shown  iu 
Fig.  17,  located  in  the  socket  of  the  vertical  attachment,  and  a 
short,  stiff,  centering  drill.  We  space,  centre,  and  drill  the 
holes  to  the  number  required  in  their  approximately  correct  po- 
sition, leaving  them  somewhat  under-size  and  in  their  accurate 
location  to  each  other.  To  size  and  finish  the  holes,  a  spindle 
should  be  turned  to  fit  the  socket  of  the  vertical  attachment  and 

a  small  cutter  inserted  in  the  protruding  end  of  it.     Thus  we 
4 


50  TOOL-MAKING  AND 

have  a  small  boring-bar,  as  shown  in  Fig.  18.  We  next  deter- 
mine the  distance  from  the  side  of  the  boring-bar  to  the  working 
side  of  the  jig  body  with  verniers.  We  deduct  one-half  the  di- 
ameter of  the  boring-bar  and  then  move  the  table  by  means  of 
the  cross  and  longitudinal  feed-screws  the  distances  required  in 
thousandths,  and  bore  the  hole  to  the  finish  size.  The  hole  being 
finished  we  make  a  plug  and  fit  it  to  the  hole  and  insert  it,  and 
then  finish  the  remaining  holes  by  working  from  the  plug  and 
the  side  of  the  jig,  measuring  with  the  verniers  from  the  side  and 
from  the  base  with  the  height-gauge.  Afterward  we  may  drill 
and  finish  the  holes  in  the  other  sides  of  the  jig  body  in  the  same 
manner,  merely  reversing  the  jig  body  or  removing  the  vertical 
attachment  and  working  directly  from  the  miller -spindle,  as  may 
be  found  convenient. 

JIG  WOEK   ON   THE   PLAIN   MILLIKG-MACHIXE. 

While  the  most  satisfactory  and  accurate  results  in  jig-mak- 
ing can  always  be  attained  on  the  lathe  face-plate  by  the  "  button 
method  "  or  on  the  table  of  the  universal  milling-machine  by  the 
vertical  attachment,  as  described  in  the  foregoing,  and  jobs  can 
be  done  that  would  be  wellnigh  impossible  of  accomplishment 
by  other  means,  it  must  not  be  inferred  that  the  plain  milling- 
machine  is  limited  in  its  sphere  of  usefulness  in  jig-making. 
Practice  has  proven  that  this  machine  tool  possesses  considerable 
utility  in  this  line. 

As  the  greater  number  of  jigs  required  are  rectangular  and 
have  bushing-holes  let  in  parallel  with  the  sides,  and  not  infre- 
quently the  bushing-holes  are  located  in  all  sides  of  the  jig  body, 
with  each  side  used  in  turn  as  a  bottom  to  set  the  jig  on  when 
drilling  from  the  opposite  side,  it  will  be  apparent  that  a  large 
part  of  the  work  necessary  to  construct  the  tool  can  be  conven- 
iently done  on  a  plain  miller  with  a  table  that  can  be  adjusted 
vertically.  We  will  say  that  we  have  a  jig  to  make  with  bush- 
ings let  in  from  two  parallel  sides.  First  we  square  and  scrape 
the  bottom  locating  surfaces  and  then  clamp  the  jig  body  on  the 
plain  miller-table,  setting  it  square  with  the  spindle  and  as  far 
from  it  as  possible,  so  that  we  niay  have  ample  room  between  it 


INTERCHANGEABLE  MANTJFA CTUBING. 


51 


and  the  work.  In  some  cases  it  may  be  expeditions  to  clamp  an 
angle-plate  to  the  platen  at  one  side  of  the  work  square  with  the 
spindle,  so  as  to  assist  in  locating  the  first  hole  and  proving  the 
work  as  we  proceed.  If  holes  are  to  be  put  in  all  of  the  differ- 
ent sides  and  the  jig  is  clamped  for  locating  the  holes  in  the 
second  side,  the  tool-maker  can  establish  without  trouble  the 
correct  relation  between  the  holes  by  taking  distances  from  the 
angle-plate  to  plugs  inserted  in  the  holes  first  bored,  as  per  Fig. 
19.  When  the  distance  from  the  first  hole  to  the  side  of  the  jig 
is  determined,  we  add  the  distance  the  jig  is  from  the  angle - 
plate,  and  thus  determine  how  far  the  first  hole  is  from  the  angle - 


,Miller 


Angle 
Plate' 


Fig.  19. 

plate.  With  the  rest  of  the  work  there  are  a  number  of  ways  to 
follow,  but  the  most  practical  is  to  use  the  height-gauge  to  meas- 
ure all  distances.  Another,  that  is  almost  as  good,  is  to  insert 
an  arbor  in  the  miller-spindle  and  feed  the  table  forward  until  a 
piece  of  tissue  paper  will  just  draw  out  between  the  arbor  and 
the  angle-plate.  Then  by  means  of  the  dial  on  the  longitudinal 
feed-screw  run  the  table  forward  the  required  distance.  When 
the  screw  on  the  machine  has  been  determined  to  be  correct,  one 
can  depend  on  the  dial  almost  wholly  for  the  vertical  spacing, 
while  the  platen  can  be  set  by  calipering  to  the  arbor  in  the 
spindle. 

In  doing  jig  work  on  the  plain-miller  a  parallel  can  often  be 
clamped  to  the  side  of  the  jig,  from  which  measurements  may  be 
taken.  After  the  work  has  been  located  in  place  on  the  table  a 
miller-vise  may  be  clamped  to  the  platen  and  a  diamond-point 
tool  clamped  in  it,  with  which  the  test  arbor  in  the  spindle  may 


52 


TOOL-MAKING  AND 


be  turned  true,  as  shown  in  Fig.  20,  finishing  it  to  size  conven- 
ient to  use  in  locating  the  work  both  horizontally  and  vertically. 
Then  again,  a  turning-tool  may  be  clamped  to  the  back  edge  of 
the  table  with  a  parallel  spanning  the  distance  to  the  first  slot  in 

Jig  Body 

r\     \    r 


Test  Arbor'  Xo°l 


FIG.  20. 

the  table,  and  in  this  way  true  a  piece  of  stock  which  may  be 
held  in  a  chuck  in  the  spindle.  Any  tool -maker  who  has  done 
much  jig  work  on  the  miller  will  appreciate  the  advantage  and 
the  help  in  having  a  test  piece  in  the  spindle  running  perfectly 
true,  and  that  in  order  to  accomplish  accurate  work  it  is  neces- 
sary to  have  all  conditions  equally  accurate  and  reliable  as  the 
job  progresses. 

It  is  sometimes  necessary  to  bore  a  bushing-hole  in  a  jig  at 
an  angle  with  one  of  its  sides.  To  do  this  correctly  on  the  plain 
miller  we  can  set  the  jig  body  at  the  given  angle  with  the  angle- 
plate — which  has  been  first  set  square  with  the  spindle — by  a 
bevel  protracter. 


HAKDLIKG   LAEGE   JIG  BODIES. 

When  work  is  to  be  handled  that  is  larger  than  the  capacity 
of  the  milling-machine  platen,  it  is  only  necessary  to  provide  an 
auxiliary  platen  almost  as  long  as  the  machine  table  and  about 
twice  its  width,  and  bolt  it  to  the  machine.     This  emergency 


INTERCHANGEABLE  MANUFA CTUBING. 


53 


table  should  be  provided  with  a  number  of  slots  or  holes  for  fas- 
tening the  work  to  it.  Accurately  made  parallels  which  just  fit 
the  slots  in  the  table  are  of  great  convenience  in  setting  such 
large  work,  while  a  block  with  a  tongue  to  fit  the  slot  and  nearly 
as  wide  as  the  table  and  with  its  edge  milled  accurately  in  line 
with  the  spindle  axis  is  also  a  help. 

After  the  jig  is  located  and  ready  for  letting  in  the  bushing- 
hole  (whether  on  the  lathe  face-plate  or  on  the  table  of  the  uni- 
versal or  plain  milling -machine),  finishing  should  not  be  done 
with  drill  or  reamer,  for  there  will  not  be  one  chance  in  a  thou- 
sand that  the  hole  will  be  accurately  located.  The  hole  must  be 
bored  to  a  finish  in  order  to  do  a  correct  job. 

JIG  FEET. 

The  proper  feet  for  jigs  is  largely  a  matter  of  individual 
taste.  There  are,  I  believe,  quite  as  many  kinds  of  jig  feet  as 
there  are  jig  designers.  Some  even  go  so  far  as  to  prefer  having 
no  feet  at  all  on  their  jigs,  and  thus  obviate  the  possibility  of 
trouble  with  the  drill-press  table  slots. 

Figs.  21  to  30  show  a  number  of  different  kinds  of  jig  feet. 
Figs.  21  and  22  are  flat-base  types ;  Figs.  23  to  25,  cast  feet  on 


Fig.  21. 


Fig.  22. 


the  base  of  jigs.     Any  of  these  make  good  feet,  the  one  shown 
in  Fig.  23  being,  of  course,  easier  to  make  and  just  as  good  as 


54 


TOOL-MAKING. 


the  others  except  where  a  foot  of  considerable  length  is  neces- 
sary. With  steel  feet  all  sorts  and  sizes  are  used  and  give  satis- 
faction.    Figs.  26  to  30  are  types. 

In  concluding  this  chapter  it  will  not  be  amiss  to  emphasize 
the  advisability  of  becoming  practically  familiar  with  the  instal- 


FIG.  23. 


Fig.  24. 


lation  and  operation  of  the  interchangeable  system  of  manufac- 
turing. To  demonstrate  the  necessity  of  mastering  the  details  of 
the  system,  it  is  only  necessary  to  point  out  that  in  the  manufac- 
turing machine-shop  of  the  present  day  the  efficiency  of  the  ma- 
chines or  parts  turned  out  can  usually  be  judged  by  the  use  that 
is  made  of  properly  designed  and  constructed  drilling  and  milling 
fixtures  and  jigs  for  the  production  in  repetition  of  the  most 


Fig.  25. 

accurate  operations  of  the  work.  Although  it  has  been,  and  is 
still,  possible  to  obtain  satisfactory  results  without  a  large  outfit 
of  such  tools,  no  shop  can  produce  interchangeable  parts  or  du- 
plicate machines  in  large  quantities  and  sell  them  at  a  price 
which  will  compete  in  the  open  market,  unless  it  has  an  ade- 
quate equipment  of  special  jigs  and  fixtures,  and  a  man  at  the 
head  of  it  who  thoroughly  understands  their  design,  construction, 
and  use. 


FIGS.  20-30. 


CHAPTER  IV. 

Types  of  Simple  and  Inexpensive  Drilling- Jigs  ; 
Their  Construction  and  Use. 

In  order  to  discuss  the  subject  of  drilliug-jigs  exhaustively, 
I  think  it  is  best  to  follow  up  the  chapter  devoted  to  the  funda- 
mental principles  for  such  work  by  first  taking  up  the  compara- 
tively simple  class  of  such  tools  which  are  used  for  the  machin- 
ing and  duplication  of  parts  in  which  great  accuracy  is  neither 
essential  nor  desirable.  As  before  stated,  the  main  point  to  be 
always  considered  by  the  constructor  of  tools  of  this  class  is  the 
decree  of  variation  allowable  in  the  work  that  is  to  be  machined. 


A 


I 
bCJ 

oc 

oc 

c 

o 

cj 

Ob 

A^ 

B      C 

c 

C      B 

i  1  i 

-J  L_ 

1  i 

i    |       j 

TWO   TYPES   OF   VEEY   SIMPLE  DEILLING-JIGS. 

Fig.  31  is  a  plain  casting  with  two  ribs  cast  on  one  side.  The 
casting  is  first  planed  on  the  sides  A  A,  and  a  cut  is  also  taken 
off  the  ribs.  It  is  then  ready  to  be  drilled.  As  the  holes  to  be 
drilled  are  clearance  holes  for  bolts  and  studs,  no  great  accuracy 
in  the  jig  is  required.     The  jig  for  this  casting  is  shown  in  three 

views  in  Fig.  32,  and,  as  will  be 
seen,  is  about  as  simple  and  in- 
expensive to  construct  as  could 
be  devised  for  the  work.  It  con- 
sists of  one  body  casting,  D,  with 
six  projections  on  one  side  for 
the  locating-points  and  fasten- 
ing-screws. It  is  first  planed  on 
the  top  and  then  strapped  on  an 
angle-plate  on  the  miller-table,  and  the  inside  is  milled.  The 
inside  of  the  projections  F  and  E  E  are  finished  square  with 
each  other,  as  they  are  the  locating-points.  Holes  are  then 
drilled  for  the  set-screws  J  and  J  J  in  the  lugs  G  G  and  _H"  re- 
spectively.    These  screws  are  case-hardened.     In  locating  the 

55 


FIG.  31. 


56 


TOOL-MAKING   AND 


holes  for  the  bushings,  a  casting,  planed  and  ready  to  be  drilled, 
is  laid  out,  and  the  holes  are  drilled  and  reamed  in  the  posi- 
tion and  to  the  size  necessary,  so  that  they  will  coincide  with 
those  in  the  part  of  the  machine  on  which  the  casting  is  to  be 


1 


(io% 


2) 


D 


ri 


2Ug 


h-1    H 


j  mill 

L 

J        K 

L 

1  j<0h 

K         L  L  L        K 


Fig.  33. 


fastened.  This  casting  is  then  used  as  a  templet,  and  by 
means  of  the  screws  J  and  I  I  fastened  within  the  jig.  The 
holes  are  then  transferred  through  it  to  the  jig,  enlarged,  and 
reamed  to  size.  The  bushings  L  L  L  L  and  K  K  are  then  made, 
and  hardened,  lapped,  and  ground  to  size,  and  finally  driven 
into  the  jig.  The  castings  are  drilled  by  fastening  them  within 
the  jig  and  resting  them  on  the  face  of  the  ribs.  This  jig  is  easy 
to  handle  and  is  a  rapid  producer. 

The  jig  used  for  drilling  the  holes  P  P  and  0  0,  in  the  casting 
Fig.  33,  is  of  a  different  type  and  is  known  as  a  " box-jig."  It 
is  in  design  one  of  the  simplest  and  most  reliable  of  jigs  suitable 
for  drilling  work  of  the  class  shown,  where  holes  have  to  be 
drilled  at  right  angles  to  each  other.  The  casting  Fig.  34  is 
machined  at  one  point  only,  M  M,  before  drilling,  by  means  of  a 
gang  of  mills,  the  size  being  exact  and  the  ends  square.  This 
milled  surface  is  utilized  as  a  locating-seat  for  the  work  when 
being  drilled.  The  jig  Fig.  34  is  in  two  parts — the  body  or  box 
casting  A  and  the  lid  E.  The  body  casting  is  first  planed  square 
on  all  sides,  and  the  inside  at  C  C  finished  off  to  fit  the  milled 
portion  of  the  casting  at  M  M.     A  cut  is  also  taken  off  the  back 


INTERCHANGEABLE  MANUFA CTURING. 


57 


N 


°1 

III  111 

"oT" 

°1 

■o: 

o 

:r'i 

oj 

u 

i:ii 

II    111 

O! 

at  D  for  the  side-locating  point  for  the  work.  The  lid  E  is  fast- 
ened to  the  body  casting  at  each  end  by  means  of  the  screws  and 
dowel -pins.  Two  holes  are  then  drilled 
and  reamed  through  the  lid  E  and  the 
base  A  for  the  taper  locking-pins  1 I, 
which  are  of  Stubs  steel  and  are 
milled  flat  on  one  side  and  hardened. 
The  centres  for  the  two  bushings  G 
G  in  the  side  of  the  jig,  and  the  four 
II  H  H  H  in  the  Md  are  accurately 
located  by  setting  the  jig  on  the  sur- 
face-plate and  locating  the  centres  by 
the  use  of  a  Brown  &  Sharp©  height-gauge.  The  centres  are  then 
prick-punched,  and  circles,  of  the  diameter  to  which  the  holes  are 
to  be  finished,  struck  around  them  with  the  dividers.  Now  when 
holes  are  to  be  bored  an  exact  distance  apart — that  is,  to  the 
smallest  possible  fraction  of  an  inch — the  only  way  to  accoinj)lish 


Fig.  33. 


this  successfully  is  to  use  buttons  and  to  strap  the  jig  on  the 
face-plate  of  the  lathe,  and  accurately  locate  them  by  means  of  an 
indicator;  but  in  a  jig  where  a  generous  limit  of  error  is  al- 
lowed, as  in  this  case,  a  simple  and  more  expedient  means  may 


58  TOOL-MAKING  AND 

be  used.  The  best  and  most  reliable  way  is  to  strap  the  jig  on 
the  table  of  the  miller  and  locate  the  drill  true  and  central  with 
the  reference  hole,  after  which  the  other  holes  may  be  located  by 
moving  the  table  forward  or  backward,  or  raising  it  the  proper 
distance,  by  means  of  the  dial  on  the  feed-screws.  In  fact,  all 
bushing-holes  in  jigs  of  this  kind  should  be  drilled  in  this  man- 
ner, and  not  on  the  drill -press,  as  it  is  pure  luck  when  satisfac- 
tory results  are  attained  with  the  latter  method,  and  that  factor 
is  a  poor  and  unreliable  one  to  depend  on.  After  the  bushings 
are  made,  hardened,  and  driven  into  their  respective  positions, 
as  shown,  and  the  clamping-screw  J  made  and  entered  into  the 
lid  E,  the  jig  is  complete. 

To  use  the  jig  the  casting  Fig.  33  is  slipped  into  it  so  that  the 
points  M  M  are  located  at  G  0  in  the  jig.  The  clamping-screw 
J"  is  then  tightened  and  the  two  taper-pins  entered  with  the  flat 
face  of  each  against  the  work,  and  each  given  a  sharp  blow  with 
the  hammer  to  locate  and  hold  the  Work  tightly  and  positively 
in  position.  The  jig  is  then  stood  up  on  the  legs  B  B,  and  the 
four  holes  OOOO  are  drilled.  It  is  then  turned  on  its  side, 
and  the  two  holes  P  P,  Fig.  33,  are  drilled.  The  clanrping-pins 
J  Tare  driven  out  and  the  screw  J  loosened,  the  finished  work 
removed,  and  another  casting  inserted.  The  use  of  the  taper 
locking-pins  II,  as  shown,  is  one  of  the  quickest  and  most  posi- 
tive means  for  the  fastening  and  locating  of  work  of  the  class 
here  mentioned. 

The  two  jigs  described  embody  in  design  and  construction  a 
number  of  different  practical  points  which  can  be  adapted  for 
use  in  jigs  for  the  drilling  of  parts  which  have  first  been  finished 
at  one  or  more  points,  as  well  as  rough  castings  which  have  not 
been  finished  at  all  before  being  drilled.  Of  course,  for  the  lat- 
ter class  of  work,  except  in  special  cases,  jigs  of  the  simplest  and 
most  primitive  design  are  all  that  is  necessary,  and  they  are  not 
worthy  of  a  detailed  description. 

A   SIMPLE  FOTJRTEEN-HOLE  DEILLI^TG-JIG. 

Fig.  35  shows  a  casting  used  as  a  leg  of  a  small  automatic 
machine,  and  the  jig  for  drilling  the  holes  in  this  casting  is  of  a 
more  accurate  and  complicated  design  than  the  two  previously 


INTERCHANGEABLE  MANUFACTURING. 


5.9 


shown,  as  the  holes  drilled  in  the  bosses  A  B  C  D  are  for  shafts, 
and  must  be  exactly  the  proper  distance  apart  for  the  gears, 
which  are  afterward  assembled  on  the  shafts,  to  mesh  properly. 
The  casting,  Fig.  35,  is  first  machined  to  size  at  four  points, 
namely,  at  the  top  and  bottom  and  both  sides  of  the  bosses.  In 
all  there  are  fourteen  holes  to  be  drilled,  in  the  positions  shown. 
The  jig  used  in  drilling  the  holes  is  illustrated  in  three  views 
in  Fig.  36.  Fig.  37  is  a  plan  of  the  jig.  These  show  clearly  the 
design  and  construction,  and  very  little  description  is  necessary. 


Fig.  35. 

The  jig  proper  A  is  of  the  box  type,  and  is  made  with  the  re- 
movable lid  D.  It  is  cast  with  legs  on  three  sides — at  both  ends, 
at  B  B,  and  at  the  bottom,  at  C  C.  All  sides  are  first  machined 
square.  On  the  inside  of  the  jig,  at  E  E  E  E,  are  raised  spots 
for  the  work  to  rest  on.  This  allows  of  quickly  finishing  the 
inside,  by  merely  milling  the  face  of  the  spots  to  the  height  de- 
sired. The  locating-points  for  the  work  are  four ;  the  two  ad- 
justable locating -screws  K  H,  which  are  equipped  with  jam-nuts 
1 1,  and  the  points  at  S  S.  The  adjustable  screws  should  always 
be  used  when  castings  of  the  kind  shown  are  to  be  drilled,  as 
any  variation  in  the  different  lots  of  castings  may  be  quickly  ac- 
commodated by  adjusting  the  screws.     For  locking  and  fasten- 


60 


TOOL-MAKING  AND 


ing  the  work  against  the  locating-points,  and  within  the  jig,  two 
set-screws,  K  and  M  respectively,  and  the  eccentric  clamping- 
lever  J  are  used.     The  set-screw  M  holds  the  casting  squarely  on 


M      k ni  n    b 


o  o 

PLAN  VIEW  WITH  LID  OFF, 

SHOWING  MANNER  OF  LOCATING, 

AND  HOLDING  WORK. 


the  raised  spots  in  the  jig,  and  that  of  K  forces  it  against  the 
points  at  8  8,  while  by  giving  the  lever  J  a  sharp  turn  it  forces 
the  casting  against  the  screws  H  H  and  locks  it  in  position,  there- 
by holding  the  work  securely  without  danger  of  loosening  while 
being  drilled.  The  eccentric  clamping -lever  is  rapid  in  both 
fastening  and  releasing  the  work.  The  lid  D  is  located  on  the 
jig  by  means  of  the  dowel-pins  G  G,  as  shown  in  Fig.  38,  and 
fastened  securely  by  the  swinging  clamps  L  L. 

In  this  jig  the  holes  for  the  bushings  at  either  end,  for  drilling 
the  holes  marked  G  and  F  respectively  in  the  work  Fig.  35,  are 
drilled  in  the  milling -machine  in  the  same  manner  used  for  the 
other  jigs.  But  for  the  shaft-holes  ABC  and  D,  after  the  but- 
tons are  accurately  located,  the  lid  D,  Fig.  37,  is  strapped  on  the 
lathe  face-plate,  and  each  "button"  positively  located  with  an 


INTERCHANGEABLE  MANUFACTURING. 


61 


indicator,  and  the  holes  bored  and  reamed  to  the  finish  size  for 
the  bushings  P  P  P  P  and  R  R  respectively. 

When  using  the  jig  the  lid  D  is  removed  and  the  casting  in- 
serted within  the  jig,  as  shown  as  Q,  Fig.  36.  The  lid  D  is  then 
replaced,  locating  on  the  dowel-pins  G  G,  and  the  swinging 
clamps  L  L  are  tightened.  The  set-screw  M  is  also  tightened  and 
the  eccentric  lever  J  given  a  sharp  turn  to  locate  the  casting 
tightly  in  position.  The  holes  at  either  end  are  drilled  by  rest- 
ing the  jig  on  the  legs  B  B.  The  casting  is  then  rested  on  the 
legs  G  C,  and  the  six  holes  in  the  side  are  drilled.  The  removal 
of  the  finished  work  may  be  quickly  accomplished  by  loosening 
the  set-screws  K  and  M  and  the  lever  J,  and  then  removing  the 
lid  D. 

The  three  jigs  shown  and  described  in  the  foregoing  will 
serve  as  practical  illustrations  of  three  separate  and  distinct 


nr=o 


Fig.  37. 


types  of  jigs,  and  show  how,  by  the  use  of  simple  and  inexpen- 
sive tools,  uniform  and  satisfactory  results  may  be  obtained  at 
the  minimum  of  cost  and  to  the  maximum  of  production  in  the 
machining  of  parts  in  which,  as  stated  before,  a  limit  of  error  is 
allowed. 


62 


TOOL-MAKING   AND 


JIGS   FOE   A   BEARING-BRACKET   AND   BEARING. 

Fig.  38  shows  a  casting  of  aluminum,  used  as  the  upper  bear- 
ing bracket  of  an  electric  cloth-cutting  machine.  After  the  hole 
in  the  centre  had  been  bored  and  reamed  to  fit  the  bearing,  Fig. 
40,  at  K,  it  was  faced  off  on  the  front  and  back.  The  holes  in 
the  wings  were  to  be  all  interchangeable  with  those  in  the  motor- 
case  of  the  machine.  The  four  holes  around  the  centre  were  also 
to  be  interchangeable  with  those  in  the  bearing,  Fig.  39.  All 
these  holes  were  drilled  in  the  jig  Fig.  40.  This  was  made  in 
two  parts,  the  base  A  and  the  lid  B.  For  these  patterns  and 
castings  were  made.  There  were  four  bosses  in  the  bottom  for 
the  work  to  rest  on  while  drilling.  After  the  base  A .  had  been 
faced  off  on  the  back,  it  was  strapped  in  the  miller  and  a  cut 
taken  over  the  bosses  and  also  over  the  ends  on  which  the  lid 
rested.  A  hole  was  then  drilled  in  the  centre  of  the  base,  into 
which  a  plug,  E,  of  tool  steel,  turned  to  fit  the  centre  hole  in  the 
work  (Fig.  39),  was  driven.  The  work  was  then  placed  on  it  and 
the  stop-pin  G  let  in.  The  set-screw  R  having  been  made,  a  hole 
was  drilled  and  tapped  and  the  screw  let  in. 

The  lid  B,  of  cast-iron,  after  being  planed  on  both  sides  was 
strapped  to  the  top  of  A,  and  holes  were  drilled  for  the  two 


Fig.  39. 


dowel-pins  G  G,  which  were  then  let  through  into  A,  and  the 
holes  in  B  eased  up  so  that  the  lid  would  set  in  nicely.  A  and 
B  were  then  clamped  together  and  a  slot  milled  through  each  end 
for  the  locking-posts  1 1.  The  posts  were  made  and  finished  and 
hinged  in  A  by  pins  J  J.  Thumb -nuts  were  got  out  and  tapped 
to  screw  on  to  the  posts  freely.     The  posts  were  then  swung  over 


INTERCHANGEABLE  MANUFA  CT  UBING. 


63 


and  the  thumb-nuts  tightened,  thereby  clamping  the  lid  and  base 
together.  The  jig  was  then  stood  up  on  the  side  D,  which  had 
been  squared  with  the  back,  and  the  centre  of  the  stud  E  was 
found  on  the  lid  B  with  a  height-gauge,  the  holes  for  the  bush- 
ings were  laid  out,  centred,  drilled,  and  reamed,  and  the  bush- 


FIG.  40. 

ings  made,  hardened,  ground,  and  driven  in.  The  jig  was  then 
complete,  and  lid  was  removed,  and  the  work  (Fig.  38),  was  in- 
serted, centring  itself  on  the  stud  E.  The  set-screw  B  was 
tightened  until  the  work  was  forced  up  against  the  stop -pin  G, 
the  lid  B  was  replaced,  the  dowel-pins  C  C  locating  it,  the  lock- 
posts  were  swung  up,  the  nuts  tightened,  and  all  the  holes 
drilled,  which  completed  the  operation.  As  will  be  seen,  there 
is  just  enough  space  between  the  bottom  of  the  lid  and  the  work 
for  clearance,  which  was  all  that  was  necessary.  The  centre 
holes  in  the  castings  being  reamed  to  the  size  and  as  nearly  as 
possible  in  the  centre,  thereby  fitting  the  stud  E,  and  the  cast- 
ings being  of  uniform  size,  they  were  easy  to  handle.  The  stop- 
pin  G  and  the  screw  B  were  sufficient  for  all  requirements  of 
location.  Clearance-holes  were  drilled  in  the  bosses  on  which 
the  work  rested,  to  allow  an  easy  escape  for  the  drillings. 

Fig.  41  shows  the  jig  used  for  drilling  the  four  holes  in  the 


64  TOOL^MAKING  AND 

bearing,  Fig.  39.  As  stated  before,  they  bad  to  niatcb  those  to 
the  bracket,  Fig.  38.  The  bearing  itself  was  of  tool  steel,  turned 
and  finished  all  over  to  fit  the  centre  hole  in  Fig.  38.  The  jig 
for  drilling  was  of  the  box  type,  made  in  two  sections.  L  was 
the  base  or  jig  proper,  of  round  machinery  steel,  a  jriece  of  which 
was  chucked  and  turned  on  the  outside  and  a  hole  bored  and 
reamed  to  just  fit  the  work  at  K.  It  was  secured  and  a  thread 
of  a  coarse  pitch  cut,  leaving  only  two  threads.  It  was  then 
faced  off  and  undercut  at  the  bottom,  to  allow  the  work  0  to  set 
in,  as  shown.  The  lid  P  was  turned  and  threaded  to  fit  the 
piece  L  nicely ;  it  was  also  couriterbored  to  go  over  the  work 
and  clamp  the  face  when  screwed  down  solid.  The  outer  edge 
was  heavily  knurled  to  give  a  good  grip.     The  work  (Fig.  39), 

was  inserted  into  one  of  the  finished  pieces 

(Fig.  38),  and  the  four  holes  were  transferred 


m&M 


M 


L     through  it,  when  it  was  removed  and  inserted 
in  the  iig  L  and  used  as  a  templet,  and  the 

FIG.  41.  J   to  * 

holes  drilled  through  it  and  through  the  bot- 
tom of  the  jig  L.  The  top  P  was  then  screwed  on  and  the  holes 
transferred  to  it.  Then  they  were  enlarged  for  the  bushings, 
which  were  made  and  driven  in.  This  finished  the  jig.  The 
work  being  inserted,  the  cap  was  screwed  down  and  the  holes 
were  drilled. 


TWO   SIMPLE   DEILLIISTG-JIGS   AND   THEIE    USE. 

In  Figs.  42  and  43  respectively  are  shown  two  examples  of 
the  duplication  of  work  by  drilling  by  the  use  of  jigs  of  the  sim- 
plest possible  construction.  The  work  for  the  drilling  of  which 
these  jigs  were  used  is  also  shown,  both  jigs  being  used  on  the 
same  piece  of  work.  Although  no  great  degree  of  accuracy  is 
required  in  the  location  and  size  of  the  holes  drilled,  the  use  of 
the  jigs  saves  considerable  time  and  insures  the  desired  degree  of 
interchangeability  in  the  work. 

The  points  drilled  in  the  work  by  the  use  of  the  jig  shown  in 
Fig.  42  are  four  holes  at  D  D  D  D,  within  A  A ;  and,  by  the  jig 
shown  in  Fig.  43,  a  hole  through  each  of  the  legs  B  B.  The 
construction  and  use  of  these  two  jigs  can  be  clearly  understood 


INTEBCHANGEA BLE  MANUFA CTVBING. 


65 


from  the  illustrations,  as  well  as  the  manner  of  locating  and  fast- 
ening them  to  the  work.  As  shown,  the  usual  conditions  are 
reversed,  the  jigs  being  located  and  fastened  on  the  work  instead 


Fig.  42. 

of  the  opposite,  which  is  usually  the  case.  The  jig  shown  in 
Fig.  42  consists  of  seven  parts.  The  bushing  and  locating-plate 
G  is  of  machine  steel  finished  on  the  ends  so  as  to  fit  easily  into 
the  portion  of  the  work  between  A  A.  The  four  holes  for  the 
drill -bushings  are  located  and  bored  and  reamed  to  size,  and  the 
four  hardened  bushings  forced  in.  A  hole  is  then  drilled  and 
tapped  in  the  centre  of  the  side  G  to  admit  the  stud  E.     This 


.I.J..L 


Fig.  43. 


stud  has  about  one  inch  of  thread  on  the  outer  end  for  the  fast- 
ening nut  F,  which  is  finished  to  the  shape  shown  and  the  outside 
heavily  knurled.     When  drilling,  the  casting,  or  work,  is  stood 


66 


TOOL-MAKING  AND 


up  on  the  drill-press  table  and  the  jig  located  between  the  points 
A  A,  as  shown,  and  the  nut  F  tightened  against  the  opposite 
side.  The  four  holes  are  then  drilled  through  the  drill -bushings 
and  the  jig  removed  by  simply  loosening  the  nut  F. 

The  second  jig,  shown  in  position  on  the  work  and  in  a  side 
view  in  Fig.  43,  is  of  such  simple  construction  that  it  can  be  un- 
derstood from  the  illustrations.  The  three  pins  1 1  Jand  J  J  J 
respectively,  at  either  end  of  the  bushing-plate  G,  locate  the  jig 
on  the  legs  B  B  of  the  work,  and  the  two  holes  are  drilled 
through  the  bushings  H  H. 


TWO   DEILLIFG-JIGS   FOR  THE   SPEED-LATHE. 

In  Figs.  44,  45,  and  46  are  shown  views  of  two  drill-jigs  of 
rather  novel  character,  suggestive  of  ways  of  drilling  a  large 
variety  of  different  shaped  pieces.  Fig.  44  is  used  for  drilling 
the  hole  a  in  the  brass  piece  A  (Fig.  45)  used  for  a  basin  plug, 
a  rubber  washer  being  afterward  fastened  around  the  neck,  the 
a  hole  being  for  the  chain  ring. 

For  this  jig  a  piece  of  1-inch  round  machine  steel  was  turned 
with  a  taper-shank  to  fit  the  tail-spindle  of  the  speed-lathe, 
and  a  hole  was  drilled  through  the  body  at  E.  The  piece  was 
then  held  in  a  two-jawed  chuck,  and  this  hole  was  enlarged  and 
bored  to  the  shape  shown,  so  that  the  piece  A  would  just  fit  it. 


Fig.  44. 


The  jig  was  then  put  in  its  place  in  the  tail-spindle  and  the 
drill-hole  G  was  drilled.  The  swinging  yoke  B:  was  got  out  by 
forging  a  piece  of  steel,  machining  it  to  the  shape  shown,  and 
fastening  by  pins  I  to  two  flat  sides  milled  on  the  body  of  the 
jig ;  a  knurled  head-screw  J  secured  the  work.     A  portion  of  the 


INTERCHANGEABLE  MANUFACTURING.  67 

face  of  the  jig  was  milled  away  at  iTfor  clearance  for  the  yoke 
R,  to  allow  it  to  swing  off  and  on  freely. 

When  in  use  the  jig  was  set  in  the  tail-spindle  and  the  drill 
was  held  by  a  small  chuck  in  the  live  spindle.  The  yoke  H  was 
swung  downward  and  the  work  to  be  drilled  was  placed  in  the 
jig  at  F,  as  shown.     The  yoke  was  then  swung  up  and  the  fast- 


FIG.  45. 

ening  screw  J  tightened.  The  tail-stock  was  then  run  out,  and 
the  drill  entering  the  hole  G,  the  hole  a  was  drilled.  The  hole 
E  through  the  body  of  the  jig  allowed  an  easy  escape  for  the 
dirt  and  chips. 

In  Fig.  46  we  have  another  adaptation  of  this  style  of  drill- 
jig,  although  the  construction  is  somewhat  different.  It  is  used 
for  drilling  the  hole  B  B  in  the  screw-plug  C.  These  plugs 
were  brass  castings  and  were  finished  all  over  to  the  shape 
shown  in  section.  The  jig  for  the  holes  B  B  consisted  of  a 
piece  of  1^-inck  round  machine  steel  turned  with  a  taper- 
shank  to  fit  the  tail  stock  the  same  as  the  other.  It  was  then 
put  into  the  live  spindle  and  a  hole  P  drilled  to  R  by  using  an 
extra  long  drill  of  the  diameter  required.  The  front  of  the  hole 
P  was  nicely  rounded  with  a  hand  tool  to  allow  an  easy  entrance 
for  the  drill  when  the  jig  was  in  use.  The  jig  was  transferred  to 
the  milling-machine  and  a  section  was  milled  away  at  M  M  to  the 
depth  shown,  so  that  the  centre  of  the  flange  of  the  work  C,  when 
in  position,  would  be  in  line  with  the  drill-hole  P.  A  machine- 
steel  disk  N  was  finished  in  diameter  to  fit  the  hole  in  the  work 
C.  A  hole  was  let  through  the  centre  of  this  disk,  and  it  was 
fastened  by  the  screw  O  on  the  flat  milled  surface  of  the  jig,  cen- 
tral and  in  line  with  the  drill-hole  P.  The  spring-pin  Q  was 
made  with  a  spiral  spring  R  at  the  back  and  a  handle  at  8,  a 
clearance-chanuel  T  being  cut  iu,  thus  allowing  the  pin  Q  to  be 
pulled  back  and  the  work  released.     When  in  use  the  work  C 


68 


TOOL-MAKING   AND 


was  located  on  the  jig  by  the  disk  N.  The  tail-spindle  was  run 
out  and  the  first  hole  B  in  the  flange  was  drilled  to  the  depth 
required.  The  work  was  then  turned  around  the  disk  N  until 
the  hole  drilled  in  the  flange  was  opposite  the  locatiug-pin  Q, 
which  snapped  into  it  by  the  tension  of  the  spring  B.  The  sec- 
ond hole  in  the  flange  was  then  drilled. 

The  two  jigs  here  shown  for  use  in  the  speed-lathe  are  about 
the  least  expensive  that  could  be  devised  for  the  drilling  of  the 
work  shown,  and  it  was   surprising  the  amount  of  work  that 


FIG.  46. 

could  be  turned  out  with  them.  Jigs  of  this  design  and  con- 
struction are  very  popular  in  the  brass  shops,  where  the  speed- 
lathe  is  often  adopted  for  work  that  is  ordinarily  done  in  drill - 
presses. 

A   DEILL-JIG   FOE   ACETYLENE   GAS   BTTK^TEKS. 


The  work  to  be  drilled  was  a  solid  casting  of  composition  of 
the  shape  shown  in  Fig.  47,  which  had  been  dropped  in  a  form- 
ing-die under  the  drop-hammer  and  then  run  through  a  trimming- 
die  to  have  each  of  the  same  shape  and  size.  After  the  hole  B, 
Fig.  47,  had  been  drilled  and  tapped  in  the  monitor,  the  piece 
was  ready  for  the  jig.  This  is  shown  from  the  side  and  front  in 
Figs.  48  and  49.     0  N  B  and  Q,  Fig.  47,  are  the  holes  to  be 


INTERCHANGEABLE  3IANUFA CTUBING. 


69 


drilled  in  the  burner.     0  and  N  were  drilled  to  No.  17,  and  P 
and  Q  to  ~No.  40  drill-gauge  size.     The  small  holes  were  after- 


>,N    ox 


J 

B 

"p" 

E@- 

rL--~ 

G 

L 

i 

Fig.  47. 


Fig.  48. 


ward  soldered  at  the  top,  thereby  leaving  two  clear  passages  for 
the  gas. 

The  jig  itself  was  a  casting,  flat  at  the  back,  with  three  pro- 
jections— one  at  the  top  to  hold  the  bushings,  and  two,  L  and  II, 
at  the  base ;  also  the  two  lugs  L  L.  In  the  first  place,  a  piece  of 
T5¥-inch   thick  flat  machine  steel  was  planed  square  to  fit  the 


Fig.  49. 


inside  of  the  burner  and  act  as  a  gauge-plate  to  locate  and 
hold  it.  It  was  then  fastened  with  the  central  screw  and  the 
two  dowel-pins  F  F,  which  were  two  Stub  steel  pins  filed  on  the 


70 


TOOL-MAKING  AND 


inside  of  each  so  that  the  burner  would  drop  freely,  but  without 
play,  between  them.  Next  a  taper  hole  was  drilled  through  the 
two  lugs  E  E  and  the  lock-pin  D  fitted  in,  with  the  side  bearing 
on  the  work  flat.  The  work  B  was  then  put  in  place  and  the 
lock-pin  D  driven  in,  thereby  holding  the  work  fast  and  snug. 
The  bushings  II  I  J  and  K  were  then  made,  hardened,  and 
lapped  to  size.  The  holes  for  the  bushings  were  then  laid  out, 
drilled  and  reamed  to  size,  and  the  bushings  driven  in.  The 
drilling  was  done  in  a  two-spindle  drill.  First,  the  jig  was  stood 
up  on  the  base  M  and  the  holes  0  and  P  drilled,  then  on  the  base 
L  and  the  holes  JVand  Q  drilled;  then,  taking  out  the  lock-pin 
D,  the  work  was  easily  removed.  The  jig  worked  very  satisfac- 
torily, each  boy  drilling  from  250  to  1,050  a  day.  The  casting 
was  sunk  in  at  G  to  give  clearance  to  the  work  at  B. 


DEILLING-JIGS   FOE   ODD-SHAPED   CASTINGS. 
The  two  jigs  shown  in  two  views  each,  in  Figs.  50,  51,  and 
52  respectively,  were  used  for  the  rapid  drilling  of  the  holes  in 
the  castings  Figs.  53  and  54,  and,  as  they  proved  rapid  and  accu- 

L  y  S  L 


Fig.  50. 


rate  producers,  the  design  and  construction  of  them  may  prove  of 
interest  to  those  having  a  number  of  holes  to  drill  in  odd-shaped 
castings. 

The  first  jig,  Fig.  50,  for  drilling  the  casting  Fig.  53,  is  a 


INTERCHANGEABLE  MANUFA CTURING. 


71 


very  simple  and  inexpensive  type,  so  constructed  as  to  allow  of 
the  rapid  locating  and  fastening  of  the  work  and  the  removal  of 
the  same  when  finished.  The  casting  as  drilled  is  shown  in  two 
views  in  Fig.  53,  and  has  two  holes  A  B  drilled  in  each  of  the 


Fig.  51. 


Fig.  52. 


eight  arms.  Before  being  drilled  the  castings  are  chucked  in  the 
turret-lathe,  and  the  centre  hole  C  is  bored  and  reamed  to  size, 
and  the  hubs  are  faced. 

The  jig  Fig.  50  consists  of  two  castings,  of  which  J  is  the 
body  casting  and  T  the  lid.  There  were  openings  at  all  sides 
for  the  escape  of  the  dirt  and  drillings.  The  legs  L  on  four  sides 
and  those  at  M  M  on  back  are  finished  and  scraped,  so  as  to  be 
dead  square  with  each  other.  The  face  of  the  body  casting  is 
also  squared  with  the  sides,  so  that  the  lid  will  rest  squarely  on 
it.  Two  dowel-pins  TJ  JJ  locate  the  lid,  and  the  thumb-nuts  V 
V  are  for  fastening  it.  A  stud  of  tool  steel,  which  is  threaded  at 
both  ends  and  its  largest  diameter  finished  to  fit  snugly  the  cen- 
tre hole  C,  is  let  into  the  bottom  of  the  body  casting,  as  shown  at 
0,  and  held  rigidly  in  position  by  a  nut  P  at  the  back.  A  large 
hole  is  bored  in  the  centre  of  the  lid,  so  as  to  clear  the  nut  Q. 
The  sideway  locating-point  is  at  B.  It  consists  of  a  Stub  steel 
pin,  which  is  hardened  and  driven  into  the  body  of  the  jig.  The 
set- screw  8  is  also  hardened  and  let  in  through  the  projecting 


72 


TOOL-MAKING  AND 


lug,   and  is  used  for  forcing  the   work   against    the    locating- 
pin  B. 

The  four  bushings  X  are  let  in  as  shown,  and  the  manner  of 
locating  and  finishing  the  holes  was  as  follows:  The  body  casting 
was  strapped  to  the  table  of  the  universal  milling-machine,  and 


Ap 

A 

B 

mm 

== 

C 

BJ 

o 

A 

aT 

the  centre  of  each  hole  was  located,  and  the  hole  was  finished  in 
turn  by  the  use  of  a  Brown  &  Sharpe  height-gauge  for  locating, 
measuring  from  one  side  of  the  jig  and  from  the  miller-table,  and 
using  a  sharp  end,  mill  for  finishing,  first  drilling  the  hole  with  a 
drill  about  ^\-inch  under  size. 

The  four  holes  for  the  bushing  W  were  located  by  the  "  but- 
ton method, "  as  described  in  Chapter  III.  After  being  located, 
the  four  holes  were  drilled  and  finished  to  size  by  strapping  the 
lid  on  the  lathe  face-plate  and  locating  each  button  to  run  true 
by  the  use  of  an  indicator. 

When  using  the  jig,  the  lid  T  was  removed  by  unscrewing  the 
thumb -nuts  V,  and  the  casting  to  be  drilled  was  located  on  the 
centering -stud  0,  the  faced  hub  of  the  work  resting  squarely  on 
the  finished  boss  N.  One  of  the  angular-faced  projections  of  the 
work  is  then  forced  against  the  locating-pin  B  by  tightening  the 
set-screw  S.  The  nut  Q  is  then  fastened  securely  within  the  jig, 
as  shown  by  the  dotted  lines  in  the  plan  view  of  the  jig.  The 
holes  B  in  the  projections  are  then  drilled  through  the  bushings 
X,  that  is,  through  every  other  one  of  the  projections,  by  stand- 
ing the  jig  on  each  of  the  four  pairs  of  legs  L  in  turn.  The  jig 
is  then  rested  on  the  legs  M  and  four  of  the  holes  A  are  drilled 


INTERCHANGEABLE  MANUFACTURING.  73 

through  the  bushings  W.  The  lid  of  the  jig  is  then  removed, 
aud  the  nut  W  arid  the  set-screw  8  loosened.  The  work  is  then 
moved  and  located  so  that  the  holes  A  and  B  in  each  of  the  four 
remaining  projections  may  be  drilled.  The  operations  of  locat- 
ing and  fastening  the  "work  and  then  of  drilling  the  holes  are 
repeated. 

As  can  easily  be  seen,  the  design  and  construction  of  this  jig 
is  of  the  simplest  possible  character  consistent  with  accurate  and 
rapid  production.  Although  it  is  necessary  to  locate  the  casting 
twrice,  the  time  entailed  amounts  to  very  little,  and  is  fully  com- 
pensated for  when  the  simplicity  and  cheapness  of  the  jig  are 
considered,  as  in  order  to  drill  all  the  holes  in  one  operation  a 
far  more  complicated  jig  would  have  been  necessary. 

In  Figs.  51-52  are  shown  views  of  a  jig  of  a  rather  more  elabo- 
ate  and  complicated  design  than  the  first.  It  is  used  for  drilling 
the  holes  in  the  casting  Fig.  53,  and  finishing  the  hubs — that  is, 
the  three  holes  G  and  the  hole  through  each  of  the  lugs  F,  the  hole 
through  the  hubs  at  I  and  the  finishing  of  the  hub  at  H.  As 
shown  in  the  two  views  of  the  jig,  the  work  is  located  at  three 
points  at  each  of  the  finished  projections  or  lugs  J,  locating 
within  the  parts  D,  which  are  drilled  to  size  in  a  preceding  oper- 


ation. The  work  is  located  side  wise  against  the  two  adjustable 
stops  K,  by  tightening  the  two  set-screws  Q  against  the  work. 
The  lid  E  of  the  jig  is  hinged  within  the  body  casting  at  F  by 
the  pin  G.  Legs  are  cast  on  two  sides  and  on  the  bottom  of  the 
body  casting,   as  shown  at  B  and    C  respectivelv.     The  four 


74  TOOL-MAKING  AND 

bushings  L  are  for  drilling  the  holes  through  the  lugs  F,  and 
those  at  M,  in  the  lid,  for  drilling  the  three  holes  G.  The  method 
used  for  fastening  the  lid  while  the  work  is  being  drilled  is 
by  means  of  a  swinging-stud  and  a  nut  and  washer  I,  the  stud 
being  hinged  to  swing  free  in  the  body  casting  at  R,  a  slot  being 
let  in  it  and  in  the  lid  for  that  purpose.  Two  set-screws  P  are 
let  into  the  lid  for  locating  and  fastening  the  work  within  the  jig. 

The  two  large  bushings  0,  for  use  when  finishing  the  hubs,  are 
permanently  located  within  the  lid,  while  those  for  drilling  the 
hole  I  in  the  hubs  are  inserted  within  them  when  in  use.  When 
using  the  jig  the  work  is  located  and  fastened  within  by  the  set- 
screws  Q  and  P,  and  all  the  holes  are  then  drilled.  The  two 
bushings  N  are  then  removed,  and  the  hubs  are  faced  and  re- 
duced to  size.  The  fastening  set-screws  are  then  released,  the 
swinging-stud  I  is  thrown  back,  and  the  lid  raised,  after  which 
the  work  is  removed. 

All  the  various  parts  of  both  these  jigs,  including  the  cast- 
ings, are  made  sufficiently  heavy  and  strong  to  withstand  all 
strain  to  which  they  may  be  subjected  when  in  use.  The  man- 
ner of  locating  the  work  is  such  as  to  be  positive,  and  without  the 
possibility  of  shifting  during  the  operation  of  the  tools.  The 
means  and  points  chosen  for  the  fastening  of  the  work  within  the 
jigs  are  such  as  to  be  rapid  to  manipulate,  and  in  no  way  to  in- 
terfere with  the  drilling ;  and,  lastly,  the  design  and  construction 
of  both  jigs  are  such  as  to  dispense  with  all  unnecessary  parts 
and  labor. 

JIG  FOE  DBILLING  BOUGH  CASTINGS  IK  PAIES. 

Fig.  56  shows  two  views  of  a  drill-jig,  with  work  in  position 
for  drilling  holes  in  the  tops  of  rough  pairs  of  bracket  castings. 
These  castings  were  used  in  large  numbers  and  were  of  the  shape 
shown  in  Fig.  55.  The  three  holes  in  the  body  portion  were 
cored,  and,  as  the  pairs  were  not  machined  at  any  point  before 
drilling,  the  holes  were  used  as  locating-points  in  the  jig.  The 
jig  consists  of  a  body  casting  in  the  shape  of  an  inverted  "T," 
X  being  the  base  and  G  the  upright  which  supports  the  plate  E 
and  the  work.     The  work  is  located  in  pairs  on  either  side  of  the 


INTEBCHANGEA  BLE  MANTJFA CTTJB1NG. 


75 


upright  by  the  dowel-pins  D  D  D,  which  enter  the  cored  holes 
and  are  held  by  the  clamping  device,  a  cross-section  of  which  is 
shown  in  Fig.  57.     This  clamp  is  of  tool  steel,  with  wings  at  1 


«, 

aO 

Ao 

J 

Fig.  55. 


and  J  to  swing  over  and  clamp  the  work,  the  centre  portion  L 
being  turned  to  fit  the  semi-circular  bottom  of  the  slot  in  the 
upright  G.  A  plate  R  is  let  into  and  fastened  to  the  front  of  the 
upright  G  by  the  two  screws  N  N.  This  plate  has  a  stud  M  fast- 
ened in  the  centre  of  it,  in  line  with  the  circular  portion  L  of  the 
swivel-clamp.  The  face  of  the  stud  is  finished  to  the  same 
radius  as  the  portion  L  and  is  of  a  length  sufficient  to  allow  of  the 
face  acting  as  a  back  bearing  for  the  swivel-clamp  to  swing  on. 


Fig.  56. 


This  construction  allowed  of  making  the  clamp  in  one  piece,  and 
gave  better  results  than  if  one  of  the  wings  had  been  made  sepa- 
rate.    About  ^3g  clearance  was  given  lengthwise  to  the  circu- 


76  TOOL-MAKING  AND 

lar  portion  L  for  rapid  fastening  and  releasing  when  in  oper- 
ation. The  plate  E  serves  as  bushing-plate  and  bushings 
as  well.  It  is  of  tool  steel,  with  three  holes  at  each  side  as 
guides  when  drilling  the  holes  AAA.  The  holes  G  C  G  are 
countersunk  to  allow  a  ready  entrance  for  the  drill.  The  plate 
is  hardened  and  drawn  slightly,  after  which  it  is  ground  on  both 
sides  and  the  holes  lapped.  The  plate  is 
located  on  the  body  casting  by  two  flat- 
head  screws  F  and  two  dowel-pins  not 
shown. 

When  the  jig  is  in  use  the  clamping  de- 
vice is  swung  out  of  the  way  and  a  pair  of 
castings  are  located  on  the  jig,  dowel-pins 
I)  D  D  being  made  an  easy  fit  in  the  cored  holes.  The  swivel- 
clamp  is  then  swung  back  and  the  screw  K  is  tightened  against 
the  castings,  thus  fastening  the  work  against  the  sides  of  the 
upright  G.  The  six  holes  are  then  drilled.  This  jig  allows  of  the 
drilling  being  accomplished  to  the  required  degree  of  accuracy 
and  interchangeability  and  in  a  very  rapid  manner.  The  swivel- 
clamp,  for  fastening  the  casting  against  the  rib  sides,  can  be 
adopted  to  advantage  for  locating  and  fastening  work  of  a  vari- 
ety of  different  shapes,  whether  the  parts  are  sent  to  the  jig 
rough  or  are  first  machined  at  different  points. 

JIG   FOE   DRILLING   AND   COUNTERSINKING. 

The  jig  shown  in  Figs.  59-60  was  used  for  drilling  and  counter- 
sinking the  holes  D  in  the  casting  Fig.  58.  The  castings  before 
being  drilled  are  bored  at  A  to  a  diameter  of  1^  inches,  and 
the  hub  is  faced  at  b  b.  The  hole  D  is  required  to  be  central 
with  the  rib  G.  The  parts  comprised  in  the  jig  are:  the  body 
casting,  with  the  circular  portion  at  E,  a  base  at  P,  and  two 
feet  at  B  B ;  the  bushing  B  G  and  the  locating  and  fastening 
device  J  I  L  K  and  N.  The  portion  E  is  bored  at  the  front 
slightly  larger  than  the  hub  of  the  work,  and  is  faced  at  the  back 
for  the  nut  N.  The  bushing  G  is  hardened  and  ground  and 
forced  into  the  top.  It  is  lapped  to  fit  a  combination  drill  and 
countersink.     The  locating   and  fastening  device  consists  of  a 


INTERCHANGEABLE  MA  NUFA  CTUBING. 


77 


machine -steel  stud  with  the  nut  N,  and  is  turned  at  K  to  fit  a 
reamed  hole  at  E,  and  at  F  to  fit  the  bored  hole  in  the  casting. 


Fig.  58. 


A  half-round  groove  is  let  in  at  L  as  clearance  for  the  drill.  A 
large  head  at  J  and  a  washer  I  with  a  section  cut  out  at  M  M 
complete  it.  The  work  is  located  on  the  jig,  so  that  the  hole 
when  drilled  will  be  central  with  the  rib  G  by  entering  the  rib 


Fig.  59. 


Fig.  60 


into  the  slot  at  0.     A  slot  is  let  in  at  Q  in  the  base  as  clearance 
for  the  end  of  the  work. 

When  in  use  the  washer  I  is  slipped  off  the  locating-stud  and 


78  TOOL-MAKING  AND 

a  casting  is  located.  The  washer  is  then  slipped  over  the  neck 
of  the  stud  and  the  nut  N  tightened.  The  hole  D  in  the  work  is 
next  drilled  and  countersunk.  To  remove  the  work  all  that  is 
required  is  to  loosen  the  nut  N  and  slip  off  the  washer. 

A   JIG   FOE   DEILLING   CAMS. 

The  cams  to  be  drilled,  Fig.  61,  were  of  brass,  ^-inch 
thick,  cut  from  a  bar  of  1-inch  round  stock,  the  cutting  off 
being  done  in  the  monitor.  They  were  to  be  drilled  eccen- 
trically, as  shown,  with  a  4^-inch  drill.  Of  course,  to  drill  a 
hole  of  this  size  in  pieces  so  small  and  have  all  approximately 
alike  necessitated  a  jig  that  would  hold  them  correctly  and 
securely.  The  jig  is  shown  in  Fig.  62,  with  a  top  and  an  end 
view,  the  top  view  with  the  plate  for  holding  the  bushing  off. 
Fig.  63  shows  plate  aud  bushing. 

A  casting  was  used  for  the  jig  proper,  with  two  wings  as 
shown,  so  that  it  could  be  set  true  and  strapped  on  the  drill-table. 
The  bushing-plate  was  planed  on  the  top  and  bottom  and  fastened 
with  four  flat-head  screws  J  and  two  dowel-pins  K.  A  bushing 
L,  of  tool-steel,  with  an  4^-inch  hole,  was  then  made,  hard- 
ened, ground,  and  lapped.  The  casting,  with  the  plate  in  posi- 
tion, was  then  set  on  the  face-plate  of  the  lathe,  and  a  hole  fl- 
inch in  diameter  bored  straight  through  at  E.     The  hole  in  the 

plate  was  then  bored  out  so  that  the 
bushing  would  just  drive  in.  The  plate 
was  then  removed  without  disturbing 
the  casting,  and  a  piece  of  turned  steel 

44  -inch  in  diameter,  with  a  prickpunch 
Fig.  61.  b     , 

mark  exactly  ^-mch  from   the    centre, 

driven  into  the  hole  E  in  the  casting  tight  enough  to  keep  it 
from  turning.  The  casting  was  then  moved  sidewise  on  the 
face-plate  until  the  prickpunch  ran  true.  The  piece  of  steel 
was  then  removed  and  the  hole  E  rebored  to  1  inch  in  diam- 
eter and  g9g-inch  full,  deep;  that  is,  so  that  the  work,  Fig. 
61,  would  enter  freely.  The  casting  was  then  removed  from 
the  lathe  and  a  slot  planed  in  the  way  shown  at  N,  Fig.  62 ; 
that  is,    1^  inches  wide  at  the  front  and  running   into   the 


[—"1 


INTERCHANGEABLE  MANUFACTURING.  79 

hole  B  as  shown.  A  piece  of  steel,  C,  ^-inch  thick,  worked 
out  in  the  way  shown  to  keep  the  work  from  being  bruised, 
was  then  made.  A  ^-inch  taper  hole  was  drilled  in  A  to 
admit  the  lock-pin  D,  which  was  of  Stub  steel,  with  one  fiat 


FIG.  62. 

side  facing  the  work.  The  lock-pin  and  the  piece  C  were  both 
hardened.  G  is  a  bracket  of  sheet  steel  cut  out  and  bent  in 
the  way  shown  and  held  by  screws  II;  F  is  the  knock-out  pin, 
if  the  spiral  spring,  and  this  completed  the  jig.  The  plate,  Fig. 
63,  was  screwed  on  and  the  jig  strapped  to  the  drill-table.  The 
work,  Fig.  61,  was  dropped  in  place,  also  the  piece  C,  and  the 
lock -pin  I)  was  given  a  tap,  which  held  the  work  fast.  The  hole 
was  drilled,  the  lock-pin  removed,  and  the  knock-out  hit  sharply 


80 


TOOL-MAKING. 


with  a  hammer,  causing  the  work  and  piece  E  to  come  out 
without  any  trouble,  the  spring  R  bringing  the  knock-out  back 
in  position. 

One  thing  necessary  was  to  have  the  hole  E  in  the  casting  and 
the  hole  in  the  bushing  exactly  the  same  size  as  the  drill ;  also 

the  drill  ground  central,  thereby  leav- 
ing only  a  very  slight  burr,  as,  had  it 
been  otherwise,  it  would  have  caused 
trouble  in  removing  the  work. 

The  jigs  illustrated  and  described 
in  this  chapter  should  prove  suggestive 
for  the  devising  of  means  for  the  rapid 
and  accurate  production  of  different 
shaped  repetition  parts  which  are  to  be 
drilled.  One  thing  which  should  al- 
ways be  kept  in  mind  when  designing 
or  constructing  fixtures  for  interchange- 
able production  is  this :  the  fixtures  used  for  rough  or  simple 
shaped  castings  should,  if  anything,  produce  quicker  and  cheaper 
than  those  for  machined  or  perfectly  interchangeable  ones,  be- 
cause castings  of  the  first  type  are,  as  a  rule,  sold  at  such  a 
low  cost  that  unless  they  are  j)roduced  very  rapidly  no  profit  is 
possible. 


Fig.  fi3. 


CHAPTER  V. 

Intricate  and  Positive  Drilling-Jigs. 

As  we  are  now  about  to  take  up  descriptions  of  a  class  of 
drilling -jigs  in  which  the  utmost  accuracy  and  inter  changeability 
in  the  product  are  essential,  I  wish  to  impress  upon  the  mind  of 
the  reader  the  necessity  of  making  himself  familiar  with  the  fun- 
damental principles  and  the  most  accurate  and  practicable  means 
for  accomplishing  accurate  results  in  the  finishing  of  the  various 
parts  of  such  jigs.  For  this  reason  I  call  his  attention  again  to 
Chapter  III. ,  in  which  is  contained  all  that  will  help  the  mechanic 
to  devise  and  construct  accurate  drilling -jigs  successfully. 


JIG  FOR  DRILLING  A  MULTIPLE-CAM  BODY. 

In  Fig.  64  is  shown  a  casting  with  two  circles  of  holes  drilled 
in  face  at  A  and  B  in  the  relative  positions  shown  in  the  pro- 
jecting lugs.  As  this  casting,  when  finished,  formed  a  part  of 
an  attachment  for  an  embroidery  sewing-machine,  and  acted  as  a 
multiple  cam,  the  accuracy  of  the 
holes  had  to  be  positive.  The  jig 
used  for  drilling  them  is  shown 
in  two  views  in  Figs.  65  and  66, 
and  as  the  design  and  construc- 
tion are  clearly  shown,  very  little 
description  is  necessary.  We  will 
confine  ourselves,  therefore,  to  the 
accurate  locating  and  drilling  of 
the   work.      D,    Fig.    65,    is  the 

body  casting,  finished  on  all  sides,  as  shown,  the  lid  L  being 
hinged  on  one  end,  at  M.  It  is  then  swung  on  the  lathe  face- 
plate and  a  hole  is  bored  through  both,  at  Q  and  E  respec- 
tively. The  hole  E  is  to  admit  the  indexing-plate  stem  G,  and 
6  81 


Fig.  64. 


82 


TOOL-MAKING  AND 


the  hole  in  the  lid  is  for  clearance  for  the  clamping-stud  Z7and 
also  as  a  general  point  for  finishing  the  bushing-holes.  The  in- 
dex-plate is  a  forging ;  the  plate  F  is  of  tool  steel,  and  the  stems 
H  and  G  of  mild  steel.  The  stem  H  is  finished  to  fit  snugly  the 
centre  hole  in  the  casting  Fig.  64,  and  is  tapped  for  the  clamp- 
ing-stud TJ.  The  stem  G  fits  the  hole  in  the  base  at  E,  and  is 
shouldered  and  threaded  for  the  washer  I  and  nut  J.  The  plate 
proper  F  is  indexed  to  six  and  is  hardened ;  then  it  is  ground  and 
the  notches  lapped  to  a  gauge,  so  that  the  divisions  are  spaced  to 
the  utmost  accuracy.  As  a  positive  locator  for  the  work  the  best 
point  is  the  key  way  at  C,  Fig.  64 ;  but  before  letting  in  the  key 
in  the  stem  H  of  the  index-plate,  Fig.  65,  the  bushing-holes  in 
the  lid  L  are  finished. 

For  this  operation  an  arbor  is  turned  up — one  end  tapering  to 
fit  the  driving-head  of  the  universal  milling-machine,  and  the 
other  a  driving  fit  within  the  hole  Q  in  the  lid.  The  lid  is  then 
forced  onto  it  and  the  arbor  driven  into  the  head,  which  is  set  on 
the  extension  plate  facing  the  spindle.  A  small  centre  drill  is 
first  used  and  the  table  set  to  allow  of  centring  the  holes  on  the 


.(NAMING  8uA»l>6a 


Fig.  65. 


proper  radius.  Three  holes,  T,  Fig.  65,  are  now  drilled,  and 
then  finished  to  size  by  butt-mill  with  a  sharp  end  cut.  The 
three  outside  holes  S  are  finished  in  the  same  way,  and  located  in 
the  proper  relation  to  the  first  circle  by  using  a  standard  plug, 
entering  it  into  one  of  the  holes  T  and  then  using  the  verniers 


INTERCHANGEABLE  MANTJFA CTURING. 


S3 


to  get  the  exact  distance  from  it  to  the  side  of  the  end-mill. 
When  the  bushings  are  finished  and  driven  into  the  holes,  one  of 
the  castings  is  clamped  into  the  jig,  and  the  index-pin  TTlet  into 
the  base  of  the  jig  at  D  is  let  into  one  of  the  index  notches. 


^ 


The  casting  is  then  adjusted  until  the  holes  when  drilled  come  in 
the  position  shown  in  Fig.  64.  The  keyway  is  next  located  in 
the  stem  H  and  the  casting  removed.  After  the  key  is  let  in  the 
jig  is  complete.  -   . 

In  using  this  jig  the  work  is  clamped  in  position,  as  shown, 
and  the  holes  drilled  through  the  bushings  8  T  S  T,  which  are 
directly  opposite  one  another.  The  index-plate  is  then  moved 
one  space ;  the  first  two  holes  drilled  are  reamed  through  the  two 
extra  bushings  T  and  8,  and  four  more  holes  are  drilled  through 
the  other  bushings,  as  before.  The  principle  of  this  jig  can  be 
used  to  the  best  advantage  for  work  in  which  holes  are  to  be 
drilled  around  an  exact  radius. 


DBILLING-  AND   HUB-FACING  JIG. 

Figs.  68  and  69  show  two  views  of  jig  for  drilling  the  holes 
F  F  F  and  E  and  facing  the  hub  D  of  the  casting,  Fig.  67.  It  is 
very  rapid  in  handling  work,  as  well  as  accurate  in  production. 
It  can  be  adopted  for  finishing  work  in  which  rapidity  in  drilling 
is  the  object  sought,  as  one  lever  locks  and  positively  locates  the 
work  in  position.  Before  being  drilled  the  casting,  Fig.  67,  is 
machined  on  the  back  A ,  the  sides  G  C,  and  the  channel  B,  thus 
allowing  of  positively  locating  it.  The  jig  consists  of  one  cast- 
ing, shown  at  G  G  G,  which  strengthens  it  for  the  locking-cam 


84  •  TOOL-MAKING   AND 

K.  The  work  is  located  on  the  two  spots  H  R  on  the  bottom, 
and  on  the  sides  on  the  adjustable  screws  J  J,  while  endwise  the 
flat  piece  /locates  it  by  the  channel.     The  three  bushings  P  P  P 


are  let  in  by  the  "button"  method  described  in  Chapter  III,  as 
is  also  the  hole  for  the  facing-bushing  N,  while  the  bushing  for 
the  hole  E,  Fig.  67,  is  ground  to  fit  the  inside  of  bushing  H. 

The  clamping-  and  locating-cam  K  M  and  L  is  made  so  that 
the  portion  K  will  press  down  the  work  on  the  spots  H  H  and 
carry  it  against  the  plate  J;  while  the  portion  L  is  finished  to  a 
slight  pitch  on  the  inner  face — as  shown  at  8,  Fig.  70 — which 
forces  it  against  the  screws  J  J.     When  in   nse  the  work  is 


Fig.  68. 


clamped  within  the  jig,  as  in  Fig.  6S,  by  pulling  down  on  the 
lever  M  of  the  locking-cam.  The  bushing  0  is  then  removed 
and  the  hub  D,  Fig.  67,  is  faced.  The  bushing  D  is  next  in- 
serted, and  the  hole  E  and   also   the  three  others  are  drilled 


INTERCHANGEABLE  MANVFA CTUBING. 


85 


through  the  bushings  F  P  P.     The  locking-cam  is  thrown  back 
and.  the  work  removed  and  another  piece  inserted. 

The  locating  and  fastening  of  work  within  jigs  by  the  cam- 


lock  here  described  is  one  of  the  most  rapid  and  reliable  means 
for  accomplishing  it,  and  can  be  adopted  for  the  drilling  of  a 


Fig.  70. 


large  number  of  different-shaped  castings  where  two  or  more 
portions  have  been  machined,  so  as  to  get  the  work  at  the  locat- 
ing-points  to  a  uniform  size. 


AN   INTRICATE   JIG   FOE   TYPEWRITER  BASES. 

As  a  practical  illustration  of  an  intricate  jig  and  the  locating 
and  finishing  of  a  large  number  of  holes  to  the  maximum  of  ac- 
curacy, the  jig  illustrated  in  three  views  in  Figs.  72,  73,  and  74 
will  serve  as  an  example.  It  is  used  for  drilling  all  the  holes — 
to  the  number  of  fifty-six — in  the  casting  Fig.  71.     The  casting 


86  TOOL-MAKING  AND 

when  finished  forms  the  base  of  a  typewriter  and  must  be  abso- 
lutely interchangeable. 

In  work  of  this  kind  care  should  be  taken  to  have  all  the  cast- 
ings of  uniform  size  and  shape.  To  accomplish  this  the  pattern 
should  be  perfect  and,  in  all  cases  of  metal,  finished  at  all  points 
to  the  size  required — allowing,  of  course,  for  shrinkage  and  sur- 
plus stock  at  all  the  points  to  be  machined.  When  perfect  pat- 
terns are  made  there  is  no  doubt  of  the  result  in  the  castings. 
The  casting,  Fig.  71,  is  first  faced  on  all  projecting  lugs  and  sur- 
faces, to  gauge,  on  a  profiling  fixture.  The  design  and  construc- 
tion of  the  jig  are  clearly  indicated  in  the  three  views,  and  the 
finishing  of  all  parts  in  any  way  similar  to  those  used  on  the  other 


Fig.  71. 


jigs  is  accomplished  in  the  same  way.  The  points  of  sufficient 
interest  to  describe  in  detail  are  the  manner  of  locating  the  work, 
the  finishing  of  the  bushing-holes  and  the  clamping  devices. 

The  casting  rests  within  the  jig  on  the  four  legs  A  A  A  A, 
Fig.  71.  It  is  located  endwise  against  the  two  points  T  T",  Fig. 
72  (these  points  being  milled  to  the  radius  of  the  ends  of  the 
casting  which  locates  in  them),  and  side  wise  by  two  adjustable 
set-screws  B  B.  The  clamping  devices  are  all  located  on  the  lid 
M  and  consist  of  the  three  knurled  head-screws  AAA,  Fig.  72, 
and  of  the  cam-locks  Z  Z.  These  locks,  shown  clearly  in  Fig. 
75,  consist  of  an  eccentric  turned  stud  and  a  square  nut,  both  of 
which  are  hardened  and  located  on  the  jig  as  shown.  By  giving 
them  a  half  turn  they  force  the  work  against  the  locating-points 


INTERCHANGEABLE  MANUFA CTUKING. 


87 


Y  T  and  also  against  the  set-screws  B  B,  and  lock  securely  in 
position.  The  lid  is  located  on  the  body  of  the  jig  by  the  three 
dowel-pins  N  N  N,  and  clamped  by  the  two  swinging-clamps  0 

F    N     F 

!  ii  i  W  i 


Fig.  72.     . 

0  and  the  large  knurled  nut  P.  This  manner  of  fastening  con- 
tributes to  the  rapid  locating  and  removal  of  the  lid.  The  legs 
are  on  three  sides  of  the  jig  and  on  the  bottom.     They  are  of 

■P. 


Fig.  73. 


tool  steel,  hardened  and  lapped  in  the  way  before  described.  In 
finishing  these  legs  a  number  of  tool-makers  mill  a  square  at  the 
top — rather  an  elaborate  way ;  all  that  is  necessary  is  to  mill  a 


TOOL -MAKING  AND 


slight  flat  on  two  sides,  which  answers  all  the  requirements  and 
is  far  more  expedient. 

The  most  difficult  part  of  the  construction  is  the  finishing  of 
the  bushing-holes.     By  reverting  to  Fig.  72  it  will  be  seen  that 
O  .  P  O 


Fig.  74. 

there  are  four  sets  of  holes,  at  B  8  T  and  U,  each  set  on  a 
radius  central  with  the  centre  hole  Q.  The  first  hole  is  that  for 
the  bushing  Q,  which  is  finished  on  the  lathe  face-plate  by  the 
"  button  "  method.  This  hole  is  bored  to  a  size  really  larger  than 
necessary,  so  as  to  admit  an  arbor  which  is  located  in  the  divid- 
ing head  of  the  miller.  This  being  done  with  the  head  facing 
the  spindle,  the  first  set  of  holes  B  are  centred  and  finished  in 
the  position  shown  by  setting  the  table  and  head  so  that  the  cen- 
tre drill  is  on  the  proper  radius  with  centre  hole  Q,  and  then  in- 
dexing for  sixteen,  finishing  six  holes  B  and  skipping 
the  centre  one.  The  next  row  8  and  the  rows  T  and 
TJ  are  finished  in  the  same  way  by  lowering  the  table 
until  the  centre  drill  is  on  the  radius  required,  and 
then  indexing  for  twenty-five  and  finishing  eleven 
holes  on  the  arc  as  shown.  The  lid  is  then  removed 
and  the  four  holes  V  V  V  V  located  with  buttons, 
inserting  a  standard  plug  in  the  holes  Q  and  getting 
the  distances  from  it  and  the  side  of  the  jig  with  a 
height-gauge,  finally  finishing  the  holes  in  the  lathe. 
The  holes  WWW  and  X  X,  and  also  those  in  the 
side  of  the  jig  at  E  E  E  E  and  F  F,  all  go  through  the  same 
operation.  The  manner  of  locating  and  clamping  the  work 
in  position    and  then  drilling  all    the  holes  is  clearly  shown 


Fig. 


INTERCHANGEABLE  2LANVFA  CT URING. 


S9 


in    the  three  views   of  the  jig    and   requires  no   further  de- 
scription. 

The  design  and  construction  of  the  three  separate  and  distinct 
types  of  jigs  shown  and  described  in  the  foregoing  comprise  the 
best  principles  for  the  positive  locating,  fastening,  and  rapid 
handling  of  work  of  the  class  shown,  while  the  method  described 
for  finishing  the  bushing-holes  is  the  most  accurate  that  has  yet 
been  devised  for  accomplishing  this  part  of  the  work.  If  fol- 
lowed out  as  defined,  the  results  obtained  will  be  satisfactory 
to  all  concerned. 

TWO  DEILLIXG- JIGS  FOE  SMALL,  ACCURATE  WORK. 

In  Fig.  77  is  shown  a  drilling -jig  embodying  a  number  of 
practical  ideas.  This  jig  is  for  spacing  off  and  centring  holes 
or  punch-seats  in  small  wheels,  which  are  in  turn  used  when  sup- 
plied with  punches  for  perforating  leather  shoe  tips,  and  miscel- 
laneous service  of  that  character.  The  wheel  before  drilling  is 
shown  in  a  cross- section  at  If,  Fig.  76  ;  and  as  finished,  with  all 
holes  drilled  and  counterbored  and  the  punches  inserted,  at  H, 


Fig.  76. 


Figs.  79  and  80,  in  which  is  shown  the  machine  on  which  the 
wheels  are  used.  These  wheels  are  of  cold-rolled  machine  steel 
and  are  finished  all  over  in  the  turret-lathe. 

As  the  holes  or  seats  for  the  perforating  punches  are  usually 
very  small,  it  is  not  possible  to  drill  them  to  the  required  degree 
of  accuracy  in  one  jig;  so  two  jigs  were  used — one  for  spacing, 
locating,  and  countering  the  holes,  and  the  other  for  drilling  and 
counterboring  them.      The  jig  for   spacing  and    centring  the 


90 


TOOL-MAKING  AND 


hales  is  shown  in  Fig.  77,  and  the  jig  for  drilling  and  counter- 
boring  in  Fig.  76. 

The  spacing  and  centring  jig,  Fig.  77,  consists  of  a  flat-bot- 
tomed casting  A  with  two  standards  B  B  which  support  the  in- 
dexing device.  There  is  a  shaft  C  with  a  wide  shoulder  at  the 
front  end  to  rest  against  the  face  of  the  standard,  and  an  end  pro- 
jecting from  this  shoulder  to  fit  the  hole  in  the  wheel  and  threaded 
for  the  nut  F.  A  small  pin  in  the  face  of  the  shoulder  locates 
the  wheel  iu  position  on  the  spindle.     The  index-plate  G  has 


three  circles  of  holes,  the  number  of  the  holes  being  designed  for 
handling  as  large  a  variety  of  wheels  as  possible.  The  index- 
pin  J  is  located  in  a  swinging  arm  H,  which  swings  on  a  stud 
let  into  a  corner  of  the  back  standard  B.  A  flat  spring  K  is 
fastened  to  the  arm  with  the  end  resting  in  a  notch  in  the  index- 
pin.  Instead  of  using  bushings  to  guide  the  drills,  a  piece  of 
y^-inch  Stub  steel  is  used,  it  beiug  finished  with  a  flat  at  L  with 
three  holes  for  the  drills.  This  end  is  hardened  aud  the  oppo- 
site end  M  is  threaded  for  the  adjusting-nut  0  located  in  the 
fork  of  the  bracket  N.  This  adjustment  allows  of  marking  dif- 
ferent C3mbinations  of  holes  in  wheels  of  different  thicknesses 
by  the  use  of  the  one  drill  guide. 


INTERCHANGEABLE  MANUFA  CTUBING. 


91 


In  conjunction  with  this  drill -jig  a  small  sensative  drill  is  used, 
and  as  the  design  and  construction  are  clearly  shown  a  detailed 
description  is  unnecessary.     The  manner  of  using  the  jig,  Fig. 


Gage,  for  Setting 
Counterbore 


Fig.  78. 


77,  is  as  follows:  A  wheel  D  is  located  on  the  spindle  as  shown, 
a  drill  is  fastened  within  the  chuck  of  the  press,  and  the  table  A 
A  of  the  press  is  set  so  that  it  can  be  raised  just  high  enough  to 
centre  or  spot  the  holes.  The  index-pin  J  is  then  set  for  the  re- 
quired circle  of  holes  by  swinging  and  locating  the  arms  H. 
After  centring  the  first  hole  the  next  is  located  and  centred  by 
pulling  out  the  index-pin  J  with  the  left  hand  and  rotating  index- 
plate  G  with  the  right,  the  outside  of  the  plate  being  knurled  to 
facilitate  it. 

The  jig  for  drilling  and  counterboring  the  wheels  is  shown  in 


■  i 


FIG.  79. 


Fig.  80. 


Fig.  76.  It  consists  of  a  casting  Q  with  a  floating  spindle  8  on 
which  the  wheels  are  placed  to  be  drilled.  This  spindle  is  fin- 
ished on  the  front  end  the  same  as  the  one  used  in  the  first  jig, 


92  TOOL-MAKING  AND 

the  work  being  located  and  fastened  upon  it  in  the  same  man- 
ner, the  locating-pin  TJ  entering  the  hole  Y  in  the  wheel  W. 
Two  dowel-pins  are  let  into  extreme  corners  of  the  bottom  of  the 
jig  to  coincide  with  two  holes  drilled  in  the  table  of  the  drill- 
press,  so  located  that  the  spindle  8  will  be  in  line  with  the  centre 
of  the  drill-chuck.  By  this  means  the  holes  can  be  drilled  very 
rapidly  and  with  the  certainty  that  they  will  all  point  toward 
the  common  centre.  When  drilling  the  wheels,  the  spindle  is 
rotated  until  one  of  the  spotted  centres  is  in  line  with  the  drill. 
The  work  is  then  pressed  upward  against  it  and  the  drill  in- 
stantly locates  it  perfectly  in  line. 

The  counterboring  of  the  holes  is  accomplished  in  the  same 
manner  as  the  drilling ;  the  counterbore  being  set  to  the  required 
depth  in  the  holes  by  means  of  the  groove  X,  the  table  of  the 


FIG.  81. 

press  being  raised  until  the  face  of  the  counterbore  rests  on  the 
flat  face  Y  of  the  gauge,  which  is  slipped  into  the  spindle  holes  of 
the  jig.  The  table  is  then  set,  the  gauge  is  removed,  the  work- 
spindle  S  is  reinserted  and  the  holes  in  the  wheel  are  finished  to 
the  diameter  and  depth  required. 

The  manner  in  which  the  wheels  are  used  when  finished  is 
shown  in  Figs.  79  and  80.  R  is  the  wheel  with  the  punches  in- 
serted ;  I  is  the  pinking-cutter  for  pinking  the  edge  of  the  work ; 
A  the  body  of  the  machine ;  B  the  cutter  and  disk  spindle,  which 
is  rotated  by  hand  by  the  crank  handle  F ;  Y  a  hard-rubber  holder 
which  runs  free  and  can  be  adjusted  on  the  yoke  spindle  T  and 
raised  or  lowered  by  the  knurled  nut  0.  A  sanrple  of  the  work 
produced  is  shown  in  Fig.  81. 

JIG    FOE    DBILLING   AN    ALUMINUM-BASE    CASTING. 

Fig.  82  shows  a  base  or  stand  of  an  electrical  cloth-cutter,  a 
casting  of  aluminum,  7  ^--inches  long.  There  were  eleven  holes 
to  be  drilled  around  the  outside.     These  were  for  6-32  screws, 


INTER  CHANGE  A  BLE  MANUFA  CT  UBING. 


93 


and  were  to  hold  in  place  a  sheet-steel  shoe  the  size  of  the 
outside  of  the  casting  and  the  inside  shown  by  the  dotted  line. 
There  were  also  six  holes  drilled  in  the  depressed  part  I)  which 


Casting  to  be  drilled 
D 


Fjg.  82 


were  for  10-24  tap,  and  were  to  hold  the  standard  that  supported 
the  cutter.  Then  there  were  three  large  holes  1-j-  inches  in  di- 
ameter by  ^-inch  deep,  with  a  |--inch  hole  in  the  centre,  -g-inch 


FIG.  83. 


deep.  There  were  also  four  holes  drilled  within  each  of  these 
large  ones,  for  4-40  screws.  These  holes  were  for  plates  which 
held  rollers  for  the  machine  to  travel  on. 

The  jigs  used  for  drilling  these  holes  are  shown  in  Figs.  83 
and  85  respectively ;  in  all  there  were  thirty-five  holes,  of  which 


94  TOOL-MAKING  AND 

twenty -three  were  drilled  in  the  jig  shown  in  Fig.  83.  As  will 
be  seen,  the  jig  is  composed  of  two  main  parts,  the  top  and  bot- 
tom. The  bottom  was  a  casting,  for  which  a  special  pattern  had 
been  made,  hollowed  out  on  the  inside  to  allow  the  work  J"  to  be 
set  in,  with  clearance  all  around.  There  were  lugs  cast  in  each 
end  to  accommodate  the  swinging  studs  H  H.  After  it  had  been 
planed  flat  on  the  bottom  it  was  milled  fiat  on  the  inside,  and  the 
gauge-plate  K  made  and  fastened  with  screws  and  dowels.  This 
plate  was  for  locating  the  work,  which  had  previously  been 
milled  out  at  that  point  to  templet,  as  seen  at  D,  Fig.  82.  The 
top  plate  was  then  got  out  of  cast-iron,  planed  on  both  sides 
and  slotted  on  the  ends  for  the  lock-pins.  The  two  were  then 
strapped  together,  and  the  holes  for  the  two  dowel-pins  J  J  were 
drilled  and  reamed.  The  pins  were  made  and  driven  into  the 
bottom  piece  F ;  then  using  the  centre  of  the  gauge-plate  K  for  a 
common  centre,  all  the  holes  shown  were  carefully  located  by  the 
button  method,  and  then  trued  and  bored  in  the  lathe. 

Three  holes  were  drilled  in  the  position  shown  for  the  set- 
screws  J  J  J.  Next,  the  bushings  were  all  made,  hardened, 
ground  and  lapped  to  size,  and  driven  home.  The  lock-studs 
H  H  were  made  of  machine  steel  and  the  nuts  or  handles  G  G, 
also  of  machine  steel,  got  out  and  put  together,  and 
the  jig  was  complete.  When  using,  the  handles  G 
G  were  given  a  turn  so  as  to  allow  of  their  being 
swung  clear  of  the  plate  LJ,  which  was  then  removed 
and  the  work  inserted  within  the  plate  jP,  locating 
itself  on  the  gauge-plate  K.  The  plate  E  was  then 
replaced,  the  lock-nuts  G  G  swung  back  and  tight- 
J*-M  ened,  and  the  three  set-screws  J  J  J  also  tightened. 
When  all  the  small  holes  were  drilled,  the  large 
holes  were  drilled  and  counterbored  by  the  com- 
bination  drill   and   counterbore   shown  in   Fiff.   84. 


^ 


N 

FiG.  84. 

N  is  a  fiat  drill  inserted  within  the  counterbore;  L 
a  screw  for  adjusting  it,  and  M  a  screw  for  holding  it. 

This  is  the  style  of  jig  best  adapted  for  this  class  of  work. 
As  will  be  seen,  the  work  itself  is  of  a  shape  hard  to  hold,  and 
the  way  shown  answered  all  requirements  and  could  be  relied 
upon  to  machine  work  that  would  interchange. 


INTERCHANGEABLE  MANUFACTURING.  95 

Fig.  85  shows  the  jig  for  drilling  the  small  holes  within  the 
large  ones,  for  the  roller-plate  screws ;  this  itself  needs  little  de- 
scription to  be  understood.  As  will  be  seen,  it  was  composed  of 
a  flat  piece  of  cold-rolled  steel  worked  into  the  shape  shown,  and 
two  disks  turned  up  to  just  the  size  of  the 
large  holes  in  the  base.  They  were  then 
fastened  one  in  each  end,  so  as  to  inter- 
change in  the  large  holes.  The  holes  EI3jl5  TIHf^ 
for  the  bushings  were  then  laid  out,  fig.  85. 
drilled,  and  reamed;  the  bushings  made, 

hardened,  and  inserted,  and  it  was  all  ready.  The  jig  was 
placed  so  that  the  disks  rested  in  two  of  the  holes  L  L.  The 
holes  were  drilled  in  each,  and  one  end  of  the  jig  was  swung 
over  to  hole  A  and  the  holes  drilled  in  it.  This  proved  a 
simple  and  reliable  means  of  drilling  these  and  getting  them  all 
alike,  as  they  should  be,  as  the  roller-plates  were  blanked  and 
the  holes  in  them  pierced  in  the  press. 

The  steel  shoe  mentioned  in  the  beginning  of  this  description, 
for  the  base,  was  blanked  and  pierced  in  the  press.  So  the 
degree  of  accuracy  necessary  in  the  laying  out  of  the  holes  can 
be  easily  seen  when  it  is  understood  that  they  were  to  go  on  either 
way,  and  leave  an  equal  margin  projecting  all  around  outside  the 
edge  of  the  castings. 


CHAPTER  VI. 

The  Design  and  Construction  of  Drilling-Jigs  for 
Heavy  Machine  Parts,  etc. 

CONSTEUCTING  LAEGE  DEILLING-JIGS. 

The  introduction  of  tools  and  fixtures  for-the  production  of 
duplicate  parts  of  heavy  machinery  and  tools  has  necessitated  the 
devising  of  means  and  the  designing  of  fixtures  by  the  use  of 
which  the  part,  or  parts,  to  be  machined  could  be  handled  with 
ease  and  expedition.  The  result  has  been  that  where  the  proper 
design  and  construction  of  fixtures  has  been  carried  out,  the  fin- 
ished work  has  proved  vastly  superior  to  that  done  by  the  old 
methods. 

In  designing  and  constructing  drill-jigs  for  heavy  parts  there 
are  a  number  of  obstacles  to  be  met  and  overcome,  not  found  in 
jigs  for  the  different  classes  of  work  shown  and  described  in  the 
preceding  chapters.  They  are  in  effect  as  follows:  In  the  in- 
creased size  and  strength  of  the  jig  castings.  Then  in  the  locat- 
ing- and  fastening-points  for  the  work,  which  must  be  so  situated 
as  to  allow  the  work  to  be  located  and  fastened  within  the  jig 
quickly,  with  the  least  exertion  on  the  part  of  the  operator. 
Lastly  in  the  locating  and  finishing  of  the  drill  bushing-holes, 
which  cannot  (as  a  rule)  be  successfully  accomplished  by  the 
same  means  used  in  the  construction  of  jigs  for  small  parts. 

JIG  FOE  DEILLI]STG   A  NAILING-MACHINE   CEOSS- 

HEAD. 

The  numerous  and  various  jigs  shown  in  the  accompanying 
illustrations  show  clearly  the  most  practical  design  and  construc- 
tion for  the  various  shaped  castings  shown.  In  Fig.  86  are  three 
views  of  a  cast-iron  cross-head  for  a  nailing -machine.  This  is 
finished  at  three  points,  at  A  A,  B  B,  and  the  bottom  C  C.     The 


INTERCHANGEABLE  MANUFA CTUBING. 


97 


holes  drilled  are  eighteen  in  number ;  four  at  each  end  at  _D ;  four 
at  E,  and  six  at  F  in  the  front  projection.  The  jig  for  drilling 
them  is  shown  clearly  with  the  work  fastened  within  it  in  the 
two  views  in  Fig.  87.     It  consists  of  one  casting  with  legs  at  each 


DiF 


±3 


E 
Af    '___ 


\OF     O       OF    O       OF     O/ 


\B  B 

B 

cf^D 

D 


D 


O^  TO 


Fig.  83. 


end  at  G  G.  The  work  is  located  by  forcing  it  endwise  against 
the  two  locators  J  and  irrespectively,  by  the  set-screws  L  L  (see 
view,  Fig.  88).  Four  straps,  KKKK,  fasten  and  hold  down  the 
work  securely  on  two  raised  and  finished  spots  in  the  bottom  of 


Fifi.  87. 


the  jig.  The  bushing-holes  are  located  and  finished  by  the 
method  described  in  the  beginning  of  this  chapter.  When  in  use 
the  work  is  fastened  within  the  jig  by  slipping  it  down  on  the 
locating-points  and  tightening  all  screws  and  clamps.     The  jig  is 


98 


TOOL-MAKING  AND 


then  stood  on  end  on  the  legs  G  G  and  the  holes  are  drilled 
through  the  bushings  Q  Q,  after  which  it  is  reversed  and  the 
holes  in  the  opposite  end  drilled  through  the  bushings  P  P.  The 
large  holes  through  the  four  projections  are  then  finished  by  in- 
serting a  boring-bar  through  the  bushings  0  and  the  cored  holes 
in  the  four  projecting  lugs  of  the  cross-head,  in  which  four  cut- 
ters are  fastened,  one  end  of  the  cutter- bar  being  fastened  in  the 
drill-press  spindle,  and  the  other  end  running  in  and  passing 
through  the  hole  in  the  centre  of  the  table,  as  the  bar  is  fed 
down.  The  jig  is  as  simple  as  possible,  and  allows  the  work 
being  very  rapidly  located,  fastened,  drilled,  and  removed.     The 


projecting  lugs  on  the  sides  for  the  straps  or  clamps  K  K  K  K 
strengthen  the  ends  of  the  jig,  and  overcome  the  tendency  to 
weakness  in  the  projecting  ends.  The  use  of  a  boring-bar  with 
four  cutters  for  finishing  the  holes  E,  Fig.  86,  is  both  economi- 
cal and  productive  of  good  results,  saving  time  in  the  finishing 
of  the  holes  and  insuring  their  alignment  with  each  other  when 
finished.  The  use  of  the  clamps  for  fastening  the  work  tends  to 
the  rapid  fastening  and  releasing  of  the  same,  as  by  a  single  turn 
of  the  nuts  they  can  be  swung  on  or  off. 


DEILLING-JIG  FOE  CAST-IEOJST  IMPEESSION  EOLLEES. 

In  the  two  views  of  the  cast-iron  impression  roller  in  Figs.  89, 
90,  we  have  a  piece  of  work  that  would  be  difficult  to  handle  with- 
out the  use  of  a  jig.     The  roller  is  turned  and  finished  in  the 


INTERCHANGEABLE  MANUFACTURING. 


99 


lathe  and  then  transferred  to  the  miller  and  indexed  for  six,  and 
the  four  channels  T  T  T  T  are  milled  down  its  entire  length.  In 
each  of  these  channels  six  holes,  R,  are  drilled  and  in  the  plain 


uE 


Fig.  89. 


Fig.  90. 


side  of  the  roller  four  counterbored  holes,  W,  are  let  in.  The 
inside  of  the  roller  is  cored  out  as  shown  by  the  dotted  lines, 
with  cored  vents  at  7  7.  A  2-inch  hole  through  the  ends  at 
U  ZJacts  as  a  journal-bearing  for  a  revolving  shaft.  The  jig  is 
clearly  shown  in  the  cross-sectional  view  in  Fig.  91,  and  in  the 
top  and  end  views  of  Figs.  92,  93.  X  is  the  main  casting,  Y  the 
bushing-plate,  and  I  the  shaft  on  which  the  roller  Z  to  be  drilled 
is  fastened.  The  locating-plate  C  revolves  in  the  end  B  of  the 
jig  and  projects  through  to  the  opposite  side,  the  index-plate  P 
being  keyed  to  it  at  G  and  fastened  by  the  nut  H.  The  bush- 
ings N  are  for  the  six  holes  R  in  the  channels,  and  those  at  M 
for  the  counterbored  holes  W  W,  Fig.  90.  To  locate  the  roller 
within  the  jig  so  that  the  channels  in  which  the  holes  are  drilled 
will  be  in  line  with  the  bushings,  the  locator  D  is  used.  It  is 
fastened  within  a  channel  in  C  by  the  cap -screw  shown,  piece 

1  N.~J^L.N        N  N         N  JLn  ■ 


Fig.  91. 

D  fitting  the  channel  E  snugty,  as  shown  in  the  cross-section ; 
while  the  roller  is  fastened  to  the  shaft  I  by  the  set-screws  K. 

In  the  end  view  of  the  jig,  Fig.  92,  the  indexing-holes  in  the 
plate  F  are  shown — those  for  the  holes  in  the  channels  are  at 
R  R  R,  and  the  one  into  which  the  index-pin  J  is  entered,  four 


100 


TOOL-MAKING  AND 


LffTJPl 


Pig.  92. 


in  all.  That  for  the  counterbored  holes  is  at  Q.  The  top  view 
of  the  jig  shows  the  position  in  which  the  bushings  N  and  M  are 
located,  and  the  manner  of  locating  the  bushing-plate  by  the  four 
screws  L  and  the  two  dowel -pins  P  P.  By 
reverting  to  Fig.  91,  the  manipulation  of  the 
jig  when  in  use,  and  the  drilling  of  the  work 
will  be  understood.  The  shaft  I  and  the 
roller  Z  are  inserted,  fitting  between  the  locat- 
ing-plate  C  and  the  finished  hub  on  the  end 
A,  with  the  locator  D  in  the  first  of  the 
channels.  The  shaft  I  is  then  slipped  through 
and  set-screw  K  in  the  roller  tightened.  The 
jig  is  then  set  on  the  table  of  a  large  adjustable  multiple 
spindle-drill;  six  of  the  spindles  being  set  so  that  the  drills 
will  enter  the  six  bushings  N,  and  four  of  the  remaining  spin- 
dles so  set  that  the  counterbores  will  enter  the  bushings  M. 
The  jig  is  then  fastened  securely  to  the  press  table  by  cap-screws 
through  the  ends  at  C.  The  four  holes  W  (Fig.  84)  are  then 
counterbored,  first  removing  the  drills  from  the  other  six  spin- 
dles. The  counterbores  are  then  removed,  the  six  drills  refast- 
ened  to  the  spindles,  and  the  index-plate  revolved  until  the  first 
channel  in  the  work  is  under  the  bushing  N.  Index-pin  J  is  now 
entered  and  the  six  holes  drilled,  when  the  index-plate  is  moved 
for  the  next  channel  and  the  holes  drilled  in  it,  the  holes  in  the 


Fig.  93. 


remaining  two  channels  being  drilled  in  the  same  manner.  The 
use  of  this  jig  together  with  the  multiple  spindle-drill  makes  the 
handling  and  drilling  of  the  heavy  roller  a  simple  operation, 
that  would,  however,  be  difficult  to  perform  satisfactorily  by 
any  other  means.  Moreover,  the  work  produced  will  be  found 
to  interchange  perfectly. 


INTERCHANGEABLE  MANUFACTURING. 


101 


DRILLING- JIG   FOR  DOVETAILED  SLIDE-BRACKETS. 

A  separate  and  distinct  type  of  jig  for  heavy  work  is  shown 
in  thethree  views  in  Figs.  94-95.  It  is  used  for  drilling  all  the 
holes  in  the  dovetailed  slide-bracket  shown  in  Figs.  96-97,  and, 
as  will  at  once  be  seen,  can  be  located  on  the  work  simply  and 


Fig.  95. 


rapidly.  The  bracket  (Figs.  98,  97)  has  four  holes  drilled  at 
V  Y  V  V  and  two  at  W  W.  The  four  holes  V  are  for  fastening 
the  bracket  to  the  body  of  the  machine  of  which  it  forms  a  part, 
and  those  at  IT  IF  for  fastening  a  spindle-bearing  to  the  portion 
on  the  bracket.  The  casting,  before  being  drilled,  is  machined 
on  the  back  at  U,  planed  dovetailed  at  8  8,  and  a  cut  is  taken 
off  the  top  at  T  T.  The  dovetailed  surface  is  utilized  as  the 
positive  locating-point  for  the  jig,  as  it  is  shown  secured  in  the 
work  in  the  two  views  of  Fig.  95.  The  bottom  of  the  jig  and 
the  point  Z  are  finished  to  coincide  with  the  dovetailed  surface 
of  the  work.  The  angular-faced  clamp  A  is  forced  up  against 
the  work  by  the  two  set-screws  B  B  and  drawn  up  tight  by  the 
clamping-lever  and  stud  C.  The  end  locating-point  is  at  I), 
which  consists  of  a  flat  steel  plate  fastened  to  the  overhanging 
end  of  the  jig  by  two  flat-head  screws.  The  four  bushings  F  F 
project  down  almost  to  the  face  of  the  jig,  this  being  necessary, 
as  the  casting  at  this  point  is  not  machined.  When  being  drilled, 
the  casting  rests  on  the  back  Xand  the  jig  is  located  and  fast- 


102 


TOOL-MAKING  AND 


ened  on  it  as  shown  in  Fig.  95.  The  holes  drilled,  the  jig  is 
quickly  removed  by  loosening  the  two  set-screws  B  B  and  the 
clamping-lever  C,  which  allows  the  clamp  A  to  be  slid  back  and 


1  r>v      <^  1 

r 

n 
w 

o 
w 

1    1 

!  1 

s 

^v      ^v 

— 

[zz 

s 

y        _V 

1 

1 

|U-'      w 

T 

II!      HI 

u 

Fig.  96. 

the  jig  removed.  The  design  of  this  jig  gives  a  practical  illus- 
tration of  how  simple  and  inexpensive  tools  for  the  drilling  of 
heavy  parts  can  be  constructed,  by  choosing  the  most  adaptable 
locating-points  on  the  work,  and  designing  the  jig  castings  so  as 
to  have  as  few  points  as  possible  to  machine.  When  locating 
and  finishing  the  bushing-holes  in  this  jig,  it  was  first  finished  at 
all  points  necessary,  and  then  clamped  to  the  slide-bracket,  or 
work,  which  was  in  turn  clamped  to  the  miller-table,  with  the 
top  of  the  jig  up.  The  holes  were  then  located  and  finished  by 
getting  the  distances  from  the  machined  sur- 
faces of  the  work  and  using  the  vertical  at- 
tachment, thus  doing  away  with  the  necessity 
of  first  laying  out  the  holes  on  the  work,  then 
finding  their  location  in  the  jig.  This  is  a 
very  good  plan  to  follow  when  the  shape  of 
the  jig  castings  will  not  allow  of  their  easy  fastening  to  the 
miller-table.  Moreover,  in  getting  the  distances  between  the 
bushing-holes,  the  machined  surfaces  of  the  work  are  reliable 
points  to  measure  from. 


§£ 


/Si 


'J 

FIG.  97. 


DEILLIFG-JIG  FOE   EOWEE-PEESS   BOLSTEES. 

Fig.  99  shows  still  another  jig,  in  two  views.  It  is  for  drill- 
ing all  the  holes  in  the  press-bolster  shown  in  Fig.  98.  The  cast- 
ing, as  can  be  seen,  is  a  rather  difficult  one  to  handle ;  but  by  the 


INTERCHANGEABLE  MANUFACTURING. 


103 


use  of  the  jig  the  drilling  is  accomplished  with  ease  and  expedi- 
tion. The  only  finishing  done  on  the  casting  before  drilling,  is 
to  plane  all  sides  of  the  two  oblong  projections,  as  shown  at  A  A, 


Fig.  98. 


B  B,  and  C  C,  to  gauge.     The  holes  drilled  are  the  four  D  D I)  D 

and  two  E  E,  and  one  through  each  of  the  x>rojections  F  F  F  F. 

The  jig  (Fig.  99)  is  in  two  parts,  the  lid  and  body  casting. 


Fig.  99. 


There  are  legs  on  four  sides  and  on  the  bottom.     The  casting  to 
be  drilled  is  located  from  the  two  oblong  projections  on  the  back, 


104  TOOL-MAKING  AND 

as  shown  in  the  plan  view,  by  the  locating- spots  G  I  and  H  and 
the  set-screws  K  K  and  J;  the  large  strap  L  holding  it  securely 
in  the  bottom  of  the  jig.  The  lid  is  located  by  the  two  nuts  O  0. 
The  bushings  N  through  each  of  the  projecting  lugs  on  the  face 
of  the  lid,  are  for  the  holes  through  FF  F  F  in  the  work.  The 
four  bushings  B  are  for  the  holes  D  and  those  at  Q  Q  for  the 
holes  E  E.  When  the  jig  is  in  use  the  work  is  located  and  fast- 
ened within  it,  as  shown  by  the  dotted  lines  in  the  plan  view  in 
Fig.  99.  It  is  then  rested  on  its  back  and  all  the  holes  in  the 
face  are  drilled.  The  holes  in  the  projecting  lugs  of  the  casting 
at  F  are  drilled  by  standing  the  jig  on  each  of  its  sides  in  turn 
and  drilling  down  through  the  bushings  JV.  In  this  jig  the 
amount  of  time  taken  to  locate,  fasten,  and  then  drill  the  work 
amounts  to  very  little  when  the  shape  and  bulk  of  the  casting  is 
considered.  Jigs  of  this  design  can  be  used  to  the  best  advantage 
for  the  drilling  of  heavy  castings  on  which  are  a  number  of  pro- 
jecting lugs,  and  when  holes  are  drilled  in  them  to  a  given  line, 
or  in  line  with  each  other,  as  in  the  case  of  the  casting  drilled  in 
this  one. 

POINTS  TO   BE   EEMEMBEKED. 

In  constructing  tools  of  the  class  described  in  this  chapter  a 
few  things  must  be  considered:  first,  to  construct  the  tools  as 
simple  as  possible  and  to  make  them  positive,  so  that  they  can  be 
handled  by  cheap  help  without  the  possibility  of  going  wrong. 
Also,  in  choosing  locating-points  on  the  work  for  the  jigs,  take 
the  same  ones  (wherever  possible)  for  all  succeeding  operations, 
thereby  eliminating,  as  far  as  possible,  the  margin  of  error 
which  may  be  the  result  of  preceding  operations.  For  instance, 
let  us  consider  the  upper  columns  of  drill-presses:  The  first  oper- 
ation on  such  parts  is  the  planing  of  the  angular  faces  of  the  col- 
umns. These  faces  are  then  used  as  locating-  and  truing-points 
for  the  succeeding  operations  of  milling  and  drilling.  There- 
fore, if,  when  the  columns  were  set  upon  the  planer  for  the  first 
operation,  they  were  not  set  square  with  the  ends,  the  error  was 
overcome  in  the  machining  of  the  ends  in  the  next  operation. 
Another  thing,  tools  of  the  kind  shown  should  always  be  made 
as  strong  as  possible,  so  as  to  withstand  rough  usage  without  in 


INTERCHANGEABLE  MANUFACTURING.         105 

any  way  affecting  their  accuracy.  If  the  tools  are  delicate,  the 
time  wasted  in  caring  and  looking  after  them  offsets  that  saved 
in  the  machining  of  the  work  by  their  use.  Also  have  a  place 
for  fixtures  where  they  may  be  put  out  of  the  way  when  not  in 
use ;  do  not  have  them  encumbering  the  floor,  as  is  all  too  fre- 
quently the  case  in  a  number  of  shops.  This  will  tend  to 
lengthen  their  life,  and  it  will  not  be  necessary  to  hunt  all  over 
the  shop  whenever  they  are  wanted. 


CHAPTER  VII. 

Drilling-Jigs  of  Novel  Design  and  Construction. 

Having  in  preceding  chapters  fully  described  the  most  expe- 
dient means  for  accomplishing  accurate  results  in  designing  and 
constructing  the  more  familiar  class  of  drill- jigs,  as  well  as  illus- 
trated numerous  types,  I  will  show  in  this  chapter  a  number  of 
jigs  of  special  and  novel  designs  and  describe  means  for  their 
proper  making  and  rapid  operation. 


DRILLING    HOLES    IN    A    SPIRAL    LINE    AROUND    A 

CYLINDER. 

Fig.  100  shows  two  views  of  a  jig  used  for  drilling  the  holes 
A  A  and  B  B  in  the  roller  Fig.  101.  As  will  be  seen,  the 
two  sets  of  holes  are  drilled  entirely  around  on  a  f -inch  pitch 


FIG.  100. 


spiral,  right  and  left  respectively.      When  finished  the  rollers 
have  hardened  pins  inserted  in  the  holes,  and  act  as  cams  for 

106 


FlCx.  101. 


INTERCHANGEABLE  MANUFACTURING.         107 

moving  small  slides  of  an  automatic  machine.  The  jig,  Fig. 
100,  although  simple  in  design  and  construction,  is  very  accurate 
in  production,  and  possesses  some  novel  features  seldom  met  with 
in  drill- jig  design.  The  jig  consists  of  the  body  casting,  of  which 
A  A  are  the  legs,  and  B  the  bush- 
iug-  and  pin-plate.  The  roller  tt  7~. 
to  be  drilled  is  fastened  on  the  ^^°r 
spindle  'D  by  the  nut  shown.  jpFpii 
This  spindle  moves  freely  in  the  £=^^ 
casting  at  C.  The  right  and 
left  worms  I  and  J  are  cut  to  a  f -inch  pitch,  and  are  fastened 
to  the  spindle.  The  indexer  K  is  of  machine  steel,  indexed 
to  twenty -six  and  fastened  to  the  spindle  by  the  set- screws 
L.  The  index-pin  Q  is  fastened  within  the  bracket  P  and  is 
finished  on  the  end  to  fit  the  index-notches  in  K,  the  spring  R 
keeping  it  down  tight.  The  worm-stud  0,  of  tool  steel,  is  fin- 
ished to  fit  the  worm  snugly ;  the  head  is  knurled,  and  it  is  then 
hardened.  The  end  of  the  spindle  D,  on  which  the  work  is  fast- 
ened, is  finished  with  a  shoulder  at  E  and  two  smaller  ones  at  F 
F,  the  space  between  these  two  being  reduced  to  a  size  sufficiently 
small  to  allow  for  clearance  for  the  drill  as  it  comes  through 
the  work.  The  drill-bushing  T  is  let  in  the  top  B  so  that  when 
the  spindle  projects  to  its  furthest  point  the  first  hole  drilled 
will  be  the  exact  distance  required  from  the  end  of  the  work. 

When  in  use  the  work  is  fastened  on  the  spindle  and  the  index- 
pin  8  is  placed  in  the  first  notch  of  the  index-sleeve  K,  that  is,  in 
the  position  shown  in  Fig.  100.  The  first  hole  is  then  drilled^ 
The  pin  is  now  entered  into  the  next  notch  and  the  next  hole 
drilled.  And  so  on  until  complete  circles  of  holes  are  drilled 
entirely  around  the  work ;  the  stud  O  in  the  worm  feeding  the 
spindle-back  as  the  holes  are  drilled.  As  the  last  one  in  the  first 
circle  of  holes  is  drilled,  the  spindle  is  slid  in  by  hand  and  the 
stud  O  enters  the  worm  I.  The  spindle  is  then  revolved  in  the  op- 
posite direction,  and  the  other  circle  of  holes  drilled  in  the 
same  manner  as  the  first.  The  work  is  then  removed,  and  the 
spindle  fed  back  to  the  starting-point;  another  roller  blank  is 
fastened  on  the  spindle,  and  the  operations  repeated  as  before. 
This  jig  can  be  adopted  for  the  drilling  of    holes,  on  a  given 


108 


TOOL-MAKING  AND 


pitch,  in  circular  jfieces  of  work.  Bushings  to  the  number  of 
circles  required,  may  be  used.  The  one  thing  necessary  is  to  have 
them  spaced  and  located  exactly  the  same  distance  apart ;  which 
should  be  the  same  as  the  pitch  of  the  worm. 

INDEXING -DIAL  JIG   FOE  DEILLING   SMALL   CAMS. 

Figs.  102-103  show  three  views  of  a  jig  in  which  the  indexing- 
dial  principle  is  utilized  for  the  rapid  drilling  of  the  small  cam, 
Fig.  104.  This  jig  is  so  constructed  as  to  allow  the  work  when 
finished  to  be  self -releasing.  It  consists  of  a  body  casting  A 
planed  and  finished  on  all  sides,  and  having  legs  B  B  scraped. 


FIG.  103. 


Fig.  102. 


Fig.  104. 


It  is  bored  to  admit  the  stem  D  of  the  index-  and  receiver-plate 
C,  which  has  eight  holes  F  bored  and  finished  to  allow  of  the 
work  to  be  drilled  fitting  nicely  within  them,  and  thereby  acting 
as  receivers.  The  four  holes  L  are  the  indexing-  or  spacing- 
points,  and  are  all  reamed  to  exactly  the  same  size.  The  bush- 
ing-plate H  is  fastened  by  the  dowel -pins  J  J  and  the  two  cap- 
screws  J  J.  This  is  done  before  locating  and  finishing  the  bush- 
ing-holes. The  bushings  K  K  are  let  into  the  plate  S,  as  shown, 
and  are  ground  and  lapped  to  size.  Care  is  necessary  in  the 
locating  and  finishing  of  the  bushing-holes  to  get  them  in  the  exact 
position  required,  as  it  is  necessary  to  have  the  holes  in  the  cam 


INTERCHANGEABLE  MANUFACTURING.         109 

eccentric  to  a  given  size.  The  index-pin  P  fits  snugly  in  the 
hole  in  the  plate  M,  and  the  holes  L  in  the  index-  or  receiving- 
plate.  The  spacing  and  locating  of  all  holes  for  the  bushings, 
index-pin,  and  receivers  for  the  work  are  accurately  accom- 
plished by  the  "button  method"  on  the  dividing-head  of  the 
universal  milling-machine,  in  the  manner  described  in  a  pre- 
ceding chapter.  The  receiver-holes  F  are  all  finished  to  size 
with  a  special  reamer. 

When  in  operation  one  of  the  pieces  to  be  drilled  is  placed  in 
each  of  the  eight  holes  or  receivers  F.  The  dial  is  then  fed 
around  until  the  first  two  places  are  under  the  bushings  K  K, 
when  the  index-pin  P  is  entered  into  the  hole  L  and  the  two 
pieces  of  work  are  drilled.  The  index-pin  is  now  removed;  the 
dial  revolved  one  space,  and  the  index-pin  re-entered.  This 
brings  the  next  two  pieces  under  the  bushings.  The  piece  drilled 
drops  through  the  jig  at  E ;  the  bottom  of  the  jig  being  cut  away 
at  this  point,  as  shown  by  the  dotted  lines.  The  second  piece 
drilled  remains  at  G.  Now  the  dial  is  moved  around  and  the 
empty  receivers  are  filled,  as  the  finished  work  drops  out.  As  will 
be  readily  seen,  the  design  of  this  jig  allows  of  the  continuous 
drilling  of  the  work,  without  loss  of  time  in  the  removal  of  same 
when  finished.  Moreover,  the  placing  of  the  work  in  the  empty 
receivers  can  be  accomplished  very  rapidly,  which  is  one  of  the 
best  features  of  the  jig,  as  this  part  of  the  work  is  quite  a  factor 
in  the  rapid  handling  and  production  of  small  parts  by  drilling. 
This  jig  can  be  used  to  advantage  for  the  drilling  of  holes  in 
small  parts  which  have  been  previously  machined  to  a  uniform 
size.  For  the  drilling  of  work  in  which  great  accuracy  iu  the 
product  is  desired  the  indexing-  or  spacing-holes  in  the  dial 
should  be  equipped  with  hardened-steel  bushings,  which  should 
be  lapped  to  a  size  allowing  of  a  snug  fit  for  the  index-pin,  thus 
insuring  the  accurate  locating  of  the  work  and  the  positive  fast- 
enings of  same  while  being  drilled. 

JIGS   WITH  INDEXING-PLATES. 

In  the  jigs  shown  in  Figs.  106,  108,  109,  respectively,  we  have 
two  more  adaptations  of  the  indexing-dial  principle  for  a  sepa- 
rate and  distinct  class  of  work.     These  possess  features  and  at- 


110 


TOOL-MAKING  AND 


Flu.  105. 


tachnients  which  in  design  and  construction  are  not  found  in 
any  of  the  jigs  previously  shown.  That  shown  in  Fig.  106  is 
used  for  drilling  all  the  holes  (except  the  centre  one  0)  in  the 

spider  casting,  Fig.  105 ;  that  is,  those 
marked  B  and  A,  through  the  project- 
ing lugs.  The  design  of  this  jig  is 
clearly  shown  in  three  views,  and  the 
method  of  construction  can  be  readily 
understood  from  the  description  of 
the  others.  When  in  use  the  casting, 
Fig.  105,  is  fastened  on  index-plate  H, 
Fig.  106,  by  entering  into  the  stud  K, 
and  then  fastened  by  a  nut  at  L.  It 
is  located  against  the  small  projecting  piece  O.  The  index-pin  TJ 
is  then  entered  in  one  of  the  holes  N  by  feeding  the  index -plate 
around  the  desired  distance  by  worm  C.  The  holes  through  one 
of  the'  projecting  lugs  B,  Fig.  105,  are  then  drilled  through  bush- 
ing P.  The  jig  is  now  stood  on  the  legs  B  B  B  B,  and  one  of  the 
holes  A  is  drilled  through  the  bushing  Q  at  the  back.  Index- pin 
U  is  pulled  out,  the  dial  fed  around  one  space,  and  the  next  two 
holes  are  drilled.  Index-pin  ZJis  equipped  with  a  spring  which 
keeps  it  tightly  down  on  the  plate.  The  nine  holes  M  are.  clear- 
ance-holes for  the  drill,  and  are  finished  slightly  larger  than  the 
hole  in  bushing  Q.  The  index-plate  if  is  a  good  fit  between  the 
front  and  back  of  the  jig,  to  allow  it  to  revolve  freely  without 
play  on  its  face.  The  bearings  for  the  worm-shaft  are  cast  on 
the  edge  at  B  B.  The  main  casting  is  cut  away  at  E,  as  shown, 
in  order  to  allow  of  the  handle  F  revolving  freely. 

This  jig  can  be  used  for  drilling  a  number  of  different  sizes 
of  castings  of  the  same  shape ;  that  is,  with  the  number  of  pro- 
jections reduced  or  increased  by  changing  the  index-plate,  or, 
better  still,  by  finishing  it  with  a  number  of  different  circles  of 
holes.  This  will  allow  of  indexing  any  number  of  holes  in  the 
casting  to  be  drilled — within  its  capacity — or  for  the  drilling  of 
regularly  spaced  holes  in  castings  of  a  circular  or  irregular 
shape.  The  use  of  the  worm  for  revolving  the  index-plate, 
although  not  absolutely  necessary,  is  far  preferable — whenever  the 
quantity  of  work  to  be  drilled  will  allow  of  the  extra  expense — 


INTERCHANGEABLE  MANUFACTURING. 


Ill 


to  the  usual  way  of  revolving  the  plate  by  haud ;  for  by  having  a 
worm  a  fair  fit  iu  the  hobbecl  rim  of  the  index-plate,  it  contrib- 
utes to  the  strengthening  and  rigidity  of  the  plate  while  the 
work  is  being  drilled. 

In  Figs.  108-109  we  have  the  other  adaptation  of  the  dial 
principle,  as  used  for  the  finishing  of  work  in  a  manner  entirely 
different  from  any  other  before  shown.     The  piece  machined  in 


this  jig  is  shown  in  Fig.  107.  It  is  a  drop-forging  and  is  first 
machined  at  three  points  at  the  back  at  A  A  A  on  a  milling  fixt- 
ure. The  centre  hole  8  is  bored  and  reamed  to  size,  and  the  top 
C  is  faced  in  a  special  chuck  in  the  turret-lathe.     The  remaining 


112 


TOOL-MAKING  AND 


operations  necessary  to  finish  the  piece  are  all  accomplished  by 
the  use  of  the  jig  shown  in  plan  and  cross-sectional  views :  i.e.,  the 
drilling  of  the  hole  D,  Fig.  107,  in  the  centre  of  each  end; 
the  facing  of  the  top ;  the  finishing  of  the  parts  E  by  a  hollow 
mill ;  the  facing  of  the  wide  surface  of  shoulders  F,  and  the  fin- 
ishing of  the  half-round  bearings  G  G.  As  this  jig  is  of  a  novel 
and  special  design,  a  detailed  description  of  the  practical  points 
necessary  to  its  successful  construction  is  essential. 

The  body  or  base  of  the  jig  is  of  cast-iron,  with  a  slot  B  at 
either  end  for  clamping  it  to  the  drill-press  table.  The  three 
raised  surfaces  E  and  F  F  locate  the  work.  The  lugs  C  C  are 
the  side  locating-points,  and  those  at  D  D  are  for  the  set-screws 
H  H.     Base  A  is  first  planed  on  the  bottom,  and  the  projections 


Fig. 107. 


are  finished  to  the  height  shown.  It  is  now  strapped  on  the 
lathe  face-plate,  and  bored  and  threaded  for  the  central  locating- 
and  fastening -stud,  which  is  of  tool  steel,  turned  and  finished  to 
the  shape  shown.  This  stud  is  threaded  at  S  to  screw  tightly 
into  base  A,  and  at  E  to  fit  the  centre  hole  in  the  work  0,  and 
is  reduced  for  the  rest  of  its  length  to  the  size  shown  at  Q. 
Finally,  the  end  C  is  threaded  for  the  nut  V.  The  locating-points 
C  C  are  finished  so  that  when  the  work  0  is  forced  against  them  by 
the  set-screws  H  H,  it  will  be  in  the  position  shown  in  the  plan 
view  of  Fig.  108.  The  dial  or  bushing-plate  P  is  of  cast-iron, 
finished  all  over,  and  bored  and  reamed  in  the  centre  to  fit  snugly 
the  locating-stud  Q.  The  holes  for  the  six  bushings  I  IKK 
and  J  J  are  located  and  finished  to  the  size  required  on  the 
lathe  face-plate,  care  being  taken  to  get  the  centres  of  all  six  on 
the  radius  required,  and  to  space  them  accurately.     Next,  the 


INTERCHANGEABLE  MANUFACTURING. 


113 


bushings  are  made,  hardened,  ground,  and  lapped  to  size,  and 
forced  into  their  respective  holes  in  the  plate  P. 

Before  locating  the  six  indexing-holes  L,  one  of  the  forgings, 
Fig.  107,  was  laid  out  and  strapped  on  the  lathe  face-plate,  and 


Fig.  108. 

the  hole  D  at  either  end  bored  and  reamed  to  size.  This  forging 
was  then  fastened  within  the  jig,  Fig.  109,  and  used  for  locat- 
ing the  first  index-hole  in  the  following  manner:  Two  steel 
plugs  were  turned  to  size,  to  lit  the  bushing  1 1  and  the  holes 
1)  D,  in  the  work.  By  inserting  these  plugs  through  the  bush- 
ings, the  bushing-plate  P  was  accurately  located  rigidly  in  posi- 
tion. The  first  index -hole'  was  now  drilled  through  the  plate  P 
and  into  the  projection  If  of  the  base  A.     Next,  the  hole  wa3 


section  on  x  y 
Fig.  109. 


reamed  with  a  taper  reamer  until  the  taper-locating  or  index-pin 
N  entered  to  the  depth  shown  by  the  dotted  lines  in  the  cross- 
section,  Fig.  109.     Bushing-plate  P  was  then  removed,  and  the 


114 


TOOL-MAKING   AND 


five  remaining  index-holes  L  located  and  reamed  to  size  on  the 
dividing-head  of  the  universal  milling-machine.  All  the  parts 
were  assembled,  as  shown  in  the  two  views,  and  the  jig  was  com- 
plete and  ready  for  work. 

For  nse  the  jig  is  bolted  on  the  table  of  an  adjustable  multi- 
ple spindle-drill,  and  two  of  the  spindles  set  so  that  the  drills 
will  enter  the  bushings  II.  The  arms  of  the  drill-press  are 
adjusted  to  bring  the  spindles  into  proper  line  and  are  then 
clamped.  The  holes  D  D  in  the  work,  Fig.  107,  are  drilled, 
then  the  drills  are  removed,  the  nut  V  loosened,  and  the  bushing- 
plate  P  is  revolved  one  space.  Index-pin  N  is  now  re-entered 
and  nut  V  tightened,  which  brings  the  facing-bushings  J  J"  in 
line  with  the  work.  The  top  being  then  faced,  the  plate  is  re- 
volved one  space  and  the  bushings  K  are  brought  in  line.  Next, 
the  lower  shoulder  of  the  work  is  faced  and  the  bearings  G  G 
finished,  after  which  the  work  is  removed,  another  piece  located, 


f~M      B 


FIG.  110. 


and  the  operations  repeated  as  before.  As  will  be  seen,  the  use 
of  this  jig  insures  the  accurate  finishing  of  the  work  and  its  per- 
fect interchangeability.  Jigs  of  this  design  can  be  used  to  the 
best  advantage  on  multiple  spindle-drills. 


INTERCHANGEABLE  MANUFACTURING. 


115 


DRILLING   HOLES   IN   A  SPIDER   CASTING. 


Fig.  110  shows  three  views  of  a  jig  that  is  self-explanatory, 
and  is  merely  illustrated  to  show  how  the  drilling  of  a  number  of 
holes  in  a  piece  at  a  given  angle  to  each  other  may  be  accurately 
accomplished  in  jigs  of  the  simplest  construction.  The  work, 
Fig.  Ill,  is  fastened  within  the  jig 
on  the  stud  D  as  shown  in  Fig.  110, 
and  located  against  the  adjustable- 
screw  J  by  set-screw  K,  which  allows 
of  the  rapid  locating  and  removal  of 
the  work.  When  the  jig  is  in  use 
the  nut  L  is  removed,  the  piece  to 
be  drilled  slipped  onto  the  stud  and 

located  on  a  raised  flat  surface  on  the  inside.  The  jig  being 
stood  upon  the  first  pair  of  legs  C  C,  the  first  hole  is  drilled. 
It  is  then  stood  on  the  next  pair  of  legs,  and  another  hole  drilled, 
and  then  the  operation  is  repeated  for  the  third  hole. 


Fig.  111. 


A  DRILLING-  AND   TAPPING-JIG. 

The  jig  shown  in  Figs.  112,  113,  and  114,  was  for  drilling 
and  tapping  cast-iron  hoods  of  the  shape  shown  in  Fig.  115. 
There  are  three  bosses  projecting  from  the  hood,  equal  distances 
0 


Fig.  112. 


apart,  and  these  bosses  were  to  be  drilled  and  tapped  to  ■§ -inch, 
and  it  was  necessary  to  have  them  accurately  spaced.     After 


116 


TOOL-MAKING   AND 


Fig.  113. 


they  were   drilled  and  tapped,  a  §  -inch  tube  was  screwed  on  to 
each  of  the  holes  and  the  tubes  were  each  reamed  for  a  piston, 

the  three  pistons  meeting  in  the 
centre,  as  shown  in  the  bottom  view 
of  Fig.  115.  The  pistons  were 
worked  by  an  eccentric  and  formed 
a  part  of  a  motor.  As  will  be  seen, 
a  piece  of  this  shape  was  hard  to 
handle  and  required  reliable  means 
for  holding  it. 

The  main  piece  or  frame  of  the 
jig  was  the  casting  B,  well  ribbed 
and  strong,  with  a  good,  stiff  base 
A.  After  the  base  was  finished  it  was  planed  on  the  front,  for  the 
slide  was  of  cast-iron,  and  was  planed  and  fitted  to  slide  nicely 
within  B  B.  A  hole  M  was  then  bored  in  the  centre  of  C  and 
tapped.  Two  gibs  D  D  of  machine  steel  were  made  and  fastened 
with  screws  and  dowels,  and  scraped  until  the  slide  Cwould  slide 
freely.  The  locating-disk  K  of  cast-iron  was  then  made,  as 
shown  in  Fig.  114.  It  was  first  bored  in  the  centre  for  the  shoulder- 
screw  A,  and  then  turned  and  hollowed  out  to  just  the  size  of  the 
rim  of  the  hood,  Fig.  115,  leaving  a  wall  all  around.  The  back 
was  faced  off  and  relieved  at  O  0.  After  that  it  was  set  up  in 
the  miller  and  indexed  accurately,  locating  and  milling  three 
y  s  at  F.  It  was  also  indexed  in  thirds  at  P,  to  give  clearance  to 
the  lugs  of  the  casting.     It  was  then  fastened  so  as  to  revolve 


Fig.  1U. 


freely,  without  play,  on  the  face  of  the  slide  G,  turning  on  the 
shoulder-screw  N.  The  spring-lock  G  was  then  made  and  fast- 
ened to  the  side  of  G ;  so  that,  when  locked,  one  of  the  lugs  of 
the  work  would  be  directly  under  the  bushing  Q.     The  project- 


INTERCHANGEABLE  MANUFA  CTUBING. 


117 


ing  piece  of  the  bashing  was  fastened,  with  screws  and  dowels, 
and  the  bashing  driven  in.  The  two  studs  1 1  were  turned  and 
threaded  at  one  end  to  screw  on  to  the  shoulder,  on  the  face  of 
C.  They  were  then  tapped  out  at  the  other  end  for  the  two 
screws  shown.  A  hole  was  drilled  and  tapped  in  the  centre  for 
the  lock-screw  L.  The  parts  were  then  all  assembled  and  the 
hood  placed  within  K,  the  three  lugs  fitting  into  the  slots  P. 
The  locking-latch  H  was  swung  on,  and  the  plate  K  moved 
around  until  the  lock -pin  G,  which  was  equipped  with  a  light 
spring,  entered  one  of  the  T's.  The  lock-screw  L  was  then 
tightened,  and  the  work  was  held  fast.  The  jig  was  clamped  on 
the  table  of  the  two-spindle  drill -press  by  a  (7-clamp  at  each  end, 
and  the  hole  drilled  through  the 
bushing  into  the  work.  The  jig  was 
then  removed  and  a  stud  the  size  of 
the  hole  entered,  through  the  bush- 
ing Q,  into  the  hole  in  the  work. 
A  hole  was  then  drilled  at  B  and 
reamed  taper  through  the  slide  C 
into  the  back  at  A,  for  a  tool-steel 
pin,  which,   when  inserted  through 

the  taper  holes,  located  the  work  central  with  the  bushing.  The 
slide  N  was  then  slid  over  the  other  end  of  the  jig,  and,  when 
central  with  the  other  spindle,  it  was  held  there  and  drilled  and 
reamed  for  the  hole  B  as  before. 

The  jig  was  now  ready  for  work,  and  it  was  set  upon  the 
drill-press  and  the  work  inserted.  The  taper-pin  was  then  put 
in  place,  and  the  first  hole  drilled ;  then,  on  loosening  the  lock- 
screw  L,  the  disk  K  was  moved  around  to  the  next  notch,  the 
screw  tightened,  and  the  next  hole  drilled;  and  likewise  with 
the  other.  The  three  holes  being  drilled,  a  tapping  attachment 
was  inserted  in  the  other  spindle,  and  we  were  ready  to  go  ahead. 
The  slide  C  was  moved  over,  the  taper-pin  entered  into  B,  and 
the  tapping  accomplished  by  operating  the  same  as  before.  The 
hood  was  then  finished  and  removed  and  another  inserted.  The 
jig  was  easy  to  handle  and  the  work  was  accurately  finished. 
The  idea  of  drilling  and  tapping  in  one  operation  added  to  its 
usefulness  and  value. 


FIG.  115. 


118 


TOOL-MAKING  AND 


A   NOVEL  DBILL-JIG. 

The  work  to  be  drilled  by  the  jig  here  shown  was  a  piece  of 
steel  If  inches  long,  with  a  &  -inch  hole  reamed  through  the  cen- 
tre, and  there  were  sixteen  holes,  22-drill-gauge,  to  be  drilled 
as  shown  in  Fig.  116;  that  is,  entirely 
around  on  a  f-inch  pitch  helix.  Then 
there  were  three  holes  from  A  to  B,  Fig. 
116,  so  that  when  these  were  separated,  as 
shown  in  Fig.  118,  and  finished  on  a  milling 
rig,  they  would  form  two  perfectly  fitting 
cams,  which,  in  a  friction-clutch  that  we 
were  making,  would  open  and  close  by 
the  aid  of  two  fingers,  not  shown.  Fig. 
117  shows  the  jig  complete. 
A  is  the  table  of  the  drill-press;  B  a  clamp,  showing  how  it 
was  secured  to  the  table ;  C  the  body,  which  was  of  cast-iron, 
planed  on  the  bottom,  with  a  hole  through  it  for  the  shaft  LJ; 


1 

1          ,' 

:  oa: 

°0i 

i  •  ' 
:     : 

o 


o 


KIG.  1J0. 


D  a  piece  of  flat  machine  steel,  1^  inches  wide  by  f-inch  thick, 
bent  in  the  way  shown  and  fastened  to  the  body  by  two  screws 
at  G  and  the  dowel-pins  H.  The  index-plate  J  was  a  piece 
of  machine  steel  2^  inches  in  diameter,  with  sixteen    grooves 


INTERCHANGEABLE  MANUFACTURING.         119 

milled  in  it  to  admit  the  lock-pin  P,  and  to  square  the  holes 
evenly.  The  worm  I  was  of  iron,  cut  ou  a  f -inch  pitch,  with  a 
cross-groove  at  0.  The  pin  R  was  driven  into  D  and  fitted 
smoothly  the  worm  as  shown.  M  was  the  lever  for  raising  the 
lock-pin,  and  N  the  spring  to  keep  it  in  the  groove  in  the  index- 
plate.  T  was  the  piece  to  be  drilled,  the  shaft  E 
being  turned  to  fit  the  ^-inch  reamed  hole,  and  the 
thread  cut  on  the  end  for  the  nut  S  to  keep  the  work 
in  place  for  the  drilling.  F  was  the  bushing,  to  fit  'No. 
22  drill.     The  index-plate  was  turned  one  space  at  a 

Fir   118 

time  and  the  pin  R  would,  in  the  course  of  sixteen 
| -inch  spaces,  cause  the  worm  J  to  make  one  complete  turn  on  the 
f -inch  pitch,  when  the  pin  L  would  be  in  line  with  the  first  of 
the  three  holes  X,  and  the  pin  R  in  line  with  the  slot  in  the 
worm  at  0.  The  pin  L  was  then  entered  with  the  first  hole,  then 
the  next  by  pulling  the  shaft  out,  and  then  the  last,  when  it 
could  be  easily  broken  apart,  the  holes  having  all  but  run  into 
each  other.  The  worm  and  index-plate  were  secured  by  set- 
screws,  as  shown. 

Four  different  sizes  of  cams  were  made,  f-inch,  -J-inch, 
1^-inch  and  1^-inch,  respectively;  and  all  that  was  necessary 
to  alter  the  jigs  was  to  take  off  the  worm  and  index-plate  and 
replace  with  other  sizes. 


CHAPTER  VIII. 

Use  of  Milling-Machines   for   Modern    Tool-Making, 

Interchangeable  Manufacturing  and 

Jobbing-Shop  Work. 

THE   UTILITY  OF   MILLING -MACHINES. 

The  development  of  precision  machine  tools  to  the  present 
high  state  of  efficiency  is  responsible  more  than  anything  else  for 
the  results  which  are  now  being  attained  in  the  making  of  tools 
and  fixtures  and  devices  for  interchangeable  manufacturing  and 
the  machining  of  repetition  machine  parts.  The  one  machine 
tool  which  has  contributed  more  than  all  others  to  the  attainment 
of  results  in  modern  tool-making  is  the  milling-machine — plain, 
universal,  and  vertical. 

The  utility  of  millers  is  by  no  means  generally  known.  To 
a  remarkable  degree  they  are  considered  adapted  only  to  tool- 
room uses  or  in  making  duplicate  parts.  As  not  every  shop  or 
factory  has  need  for  a  strictly. tool-making  department,  or  turns 
out  interchangeable  work,  investigation  into  the  many  uses  for  a 
miller  in  finishing  ordinary,  as  well  as  special,  work  is  not  car- 
ried out  as  it  should  be.  That  they  are  capable,  with  attach- 
ments, of  performing  a  wider  range  of  work  in  jobbing-shops 
than  perhaps  any  other  machine  tool,  and  at  lower  cost,  is  a  fact 
that  is  now  attracting  the  attention  of  progressive  managers. 

A  well-designed  milling-machine,    properly  constructed,  is 

to-day  recognized  as  one  of  the  most  important  tools  in  every 

well-equipped  machine-shop.     Many  operations  heretofore  done 

on  a  planer  or  shaper  are  now  done  much  more  perfectly  and 

economically  on  a  milling-machine,  and  for  this  class  of  work 

the  use  of  end-  or  surface-mills  has  recently  come  into  general 

favor,  as  this  form  of  mill  will  remove  metal  very  rapidly  and 

leave  the  surface  in  good  condition. 

120 


INTERCHANGEABLE  MANUFACTURING.         121 

The  liorizoDtal-spindle  machines  in  the  plain  or  universal 
forms  are  in  general  use  and  familiar  to  all ;  and  for  many  kinds 
of  work,  such  as  index- milling,  or  milling  of  any  kind  where 
work  is  carried  on  centres  or  held  in  head  centre ;  making  irreg- 
ular or  form  cuts  requiring  the  use  of  a  series  of  cutters  held  on 
arbor  which  may  or  may  not  be  supported  by  outward-arm; 
slot-milling,  and  a  variety  of  operations  called  for  in  every-day 
practice,  these  machines  with  spindle  in  horizontal  position  meet 
all  the  requirements  and  are  most  convenient  and  effective. 

Special  machines,  such  as  the  Lincoln  and  modified  types  of 
this  class,  are  in  use  for  duplication  of  parts ;  but  the  two  main 
types  heretofore  in  use  for  general  purposes  have  been  the  hori- 
zontal-spindle and  the  vertical-spindle  machines,  and,  as  stated, 
each  of  these  classes  have  their  decided  points  of  superiority. 

While  the  milling-machine  has  no  claim  to  antiquity,  the 
manner  in  which  it  has  been  adapted  and  used  for  all  classes  of 
fine  work,  and  the  rapidity  with  which  it  is  becoming  understood, 
have  more  than  compensated  for  its  late  birth.  Although  the 
youngest  of  the  machine-tool  brood,  it  is  now  the  most  univer- 
sally used  one  and  can  well  be  placed  at  the  head  of  them  all. 
The  modern  tool-room,  where  claims  are  laid  to  doing  good  work, 
that  is  not  equipped  with  a  universal  milling-machine  is  to-day 
a  paradox  indeed.  Still,  notwithstanding  the  fact  that  nearly  all 
shops  have  such  machines,  their  use  and  manipulation  are  not 
generally  understood ;  that  is,  we  mean  that  the  large  and  wide 
range  of  work  possible  to  machine  on  them  is  not  appreciated 
by  mechanics  in  general. 

When  we  state  that  the  use  and  adaptation  of  the  milling- 
machine  are  not  understood  as  they  should  be,  we  do  not  refer  to 
its  use  for  the  ordinary  classes  of  work,  but  to  special  work  such 
as  jigs,  tools,  dies,  and  fixtures  for  the  machining  of  repetition 
machine  parts  and  also  for  economic  manufacturing. 

As  one  writer  in  The  American  Machinist  has  aptly  said: 
"Of  all  the  machines  to  be  found  in  the  modern  tool-room  the 
universal-miller  stands  pre-eminent.  This  is  the  machine  of 
applied  geometry.  The  combinations  and  positions  obtained  by 
means  of  a  first-class  universal  are  almost  endless.  A  jig-body 
properly  set  up  in  a  universal  may  be  rotated,  swung,  twisted 


122  TOOL-MAKING  AND 

around,  raised,  lowered,  moved  laterally  or  crosswise,  set  to  any 
angle,  drilled,  bored,  reamed,  faced,  slotted,  profiled,  indexed, 
and  in  some  cases  completely  machined  and  made  ready  for  the 
bushings  without  changing  the  original  setting.  There  is  scarcely 
any  problem  in  jig-making,  no  matter  how  intricate,  that  cannot 
be  worked  out  on  a  universal  with  the  greatest  ease,  and  posi- 
tive distances,  angles,  and  arcs  in  every  direction  are  only  a  mat- 
ter of  correctly  reading  the  index-plates  or  wheels." 

IMPBOVEMENTS   m   CONSTBUCTIOK 

During  the  past  few  years  great  improvements  have  been 
made  in  the  construction  of  universal  milling-machines,  so  that 
now  they  are  adaptable  for  a  larger  variety  of  work  than  ever. 
As  incentives  to  the  further  improvements  of  such  machines, 
their  use  has  been  largely  extended  and  their  advantages  for  cer- 
tain classes  of  work  are  becoming  better  understood.  It  is  ap- 
parent that  the  constant  aim  of  the  designer  has  been  to  increase 
the  range  of  universal  milling-machines,  and  the  result  to-day  is 
that  they  are  used  for  a  variety  of  work  simply  astonishing.  The 
attainment  of  these  results  can  directly  be  traced  to  specialization 
in  manufacturing  and  to  the  employment  of  jigs,  fixtures,  and  spe- 
cial appliances  throughout  in  the  production  of  the  machines. 

TWIVEBSAL   MILLING-MACHINES. 

It  is  not  so  long  since  that  the  universal  milling-machine  was 
looked  upon  as  a  machine  useful  only  for  tool  work,  and  a  first- 
class  tool-maker  the  only  man  to  handle  it.  In  a  sense  it  was 
looked  upon  as  a  luxury  which  only  a  few  shops  could  enjoy. 
To-day  all  this  has  changed  and,  while  the  machine  is  used  for  a 
larger  and  better  variety  of  tool  work  than  ever,  it  is  in  the  pro- 
duction of  repetition  parts  that  its  great  value  has  become  ap- 
parent. Thus  this  tendency  to  the  universal  use  of  the  machines 
has  given  more  and  better  work  to  the  skilled  tool-maker ;  for 
where  large  quantities  of  parts  are  to  be  milled,  a  special  jig, 
fixture,  or  a  device  of  some  sort  is,  of  course,  necessary,  in  order 
that  the  cost  of  producing  the  parts  may  be  reduced  to  the  mini- 
mum. There  are  any  variety  of  parts  which  can  be  rapidly  and 
accurately  machined  by  simple  indexing  or  light -chucking  de- 
vices on  these  machines ;  and  as  the  economy  in  the  production 


INTERCHANGEABLE  MANUFACTURING.         123 

of  even  a  small  number  of  parts  machined,  by  their  use  usually 
more  than  pays  for  the  cost  of  the  fixtures  there  is  no  good  ex- 
cuse for  their  non -adoption. 

To-day  the  proprietor  of  any  machine,  tool,  or  die  manufac- 
turing establishment  who  wishes  to  do  everything  possible  to  as- 
sure success  must  see  first  that  his  tool-room  equipment  is  as 
complete  as  the  demands  of  his  specialty  necessitate.  He  should 
also  start  out  to  do  this  with  the  conviction  that  it  will  not  prove 
merely  an  additional  item  of  expense,  but,  on  the  contrary,  a  de- 
partment which  will  tend  to  increase  the  efficiency  of  his  product. 
While  the  first  cost  of  an  up-to-date  tool -room  equipment  is 
sometimes  staggering  to  the  person  who  pays  the  bills,  the  knowl- 
edge that  through  it  he  will  be  able  to  more  than  balance  the 
expenditure  in  a  very  short  time  should  set  his  mind  at  ease. 

The  universal  milling  machines  now  on  the  market  have  been 
designed  and  built  to  meet  all  requirements  of  tool-making  and 
manufacturing,  while  the  attachments  which  may  be  used  with  the 
machines  make  the  doing  of  a  special  or  an  intricate  job  an  easy 
matter.  With  the  attachments  now  in  use  on  the  universal  miller 
for  rotary -milling,  cam-cutting,  rack-cutting,  vertical -milling, 
under-cutting  large  gears,  and  a  variety  of  other  classes  of  work 
too  numerous  to  mention,  the  making  of  tools  of  unusual  accuracy, 
as  well  as  the  modern  manufacturing  of  machine  parts,  can  be 
carried  on  without  trouble  or  worry  on  the  part  of  the  mechanic. 

"KNEE  TYPE"  OF   UNIVERSAL   MILLING-MACHINES. 

While  fully  appreciating  the  value  and  adaptability  under 
certain  conditions  of  the  "Lincoln,"  "Slab,"  and  "Rotary 
Planer"  types  of  milling-machines,  I  devote  the  space  at  my 
command  herein  to  the  ' '  Knee  Type  ' '  exclusively.  This  type 
of  milling-machine,  on  account  of  its  wide  range  of  work,  has 
been  adapted  for  tool,  die,  experimental,  and  fine  machine 
work  all  over  the  world ;  and  therefore,  as  the  demand  for  this 
type  of  milling-machine  has  exceeded  that  for  all  other  types 
combined,  the  tendency  among  the  manufacturers  of  such  ma- 
chines has  been  to  increase  their  range  and  to  make  them  uni- 
versal in  every  sense  of  the  term. 

The-  knee-type  milling-machine  is  among  the  latest  additions 


124  TOOL-MAKING  AND 

to  the  machine-tool  family;  but  it  has  taken  its  place  in  thou- 
sands of  progressive  shops,  where  it  is  used  to  the  best  advan- 
tage as  far  as  the  knowledge  of  the  art  has  progressed  at  this 
date,  although  there  yet  remain  many  shops  where  its  advantages 
are  not  understood,  and  work  is  being  done  on  other  machines, 
or  by  hand,  when  it  could  be  done  on  a  milling-machine  at  a 
great  saving  in  cost,  if  a  little  thought  were  given  to  the  proper 
cutters  and  equipment. 

The  knee-type  universal  milling-machine  will  do  a  greater 
variety  of  work  than  any  other  machine  tool,  and  a  small  experi- 
mental shop  that  can  have  only  one  machine  will  be  best  equipped 
with  a  machine  of  this  class. 

MILLING-MACHINES   COMPAEED    WITH   OTHER 
MACHINE-TOOLS. 

Any  work  that  can  be  done  on  the  face-plate  or  in  the  chuck 
of  a  lathe  can  be  done  in  a  milling-machine  by  holding  an  ordi- 
nary lathe-tool  in  the  swivel-vise.  A  pair  of  bevel-gears,  for 
instance,  can  be  bored,  turned  on  the  angles,  teeth  cut,  and  the 
gears  finished  complete  without  ever  having  been  near  a  lathe. 
A  steam-  or  gas-engine  cylinder  can  be  bored,  faced,  and  finished 
complete,  and  the  fly-wheel  bored  and  turned  iu  the  same  ma- 
chine. 

What  a  trying  thing  it  is  to  see  a  machinist  work  up  a  num- 
ber of  parts  on  a  shaper  or  planer  and  then  see  another  spend 
a  day  or  two  filing  and  fitting  to  make  them  go  together,  while  it 
takes  a  helper  five  minutes  to  mix  them  up  and  another  machin- 
ist a  long  time  to  sort  them  out  and  assemble  in  their  proper 
places. 

By  way  of  contrast,  a  boy  could  have  made  them  absolutely . 
interchangeable  in  the    milling-machine,   and  they  could  have 
been  drawn  at  random  from  the  stock-room  and  assembled  with- 
out filing,  fitting,  or  loss  of  time. 

Formerly  it  was  supposed  that  a  milling-machine  in  the  tool- 
room constituted  a  full  equipment  in  this  line  of  machinery,  but 
lately  it  is  becoming  known  that  improvements  have  been  made 
greatly  increasing  the  power  of  the  spindle  and  feed,  as  well  as 


INTERCHANGEABLE  MANUFACTURING.         125 

adding  innumerable  conveniences,  such  as  all  automatic  feeds 
constructed  so  as  to  be  quickly  changed  from  one  to  the  other, 
and  at  the  same  time  being  impossible  for  auy  two  to  engage  at 
once.  The  knee  being  box  section,  cast  without  hole  through 
the  top,  gives  the  work-table  sufficient  rigidity  to  enable  it  to 
carry  much  larger  work  without  chatter  than  would  be  possible 
with  the  old-style  construction,  and  make  many  manufacturing 
operations  not  only  possible,  but  economical. 

An  equipment  for  the  rapid  production  of  finished  work  on  a 
milling-machine  can  be  classified  under  three  heads. 

First :  Strong,  accurate  machine  with  ample  range  and  easy 
adjustments. 

Second:  Suitable  fixtures  for  holding  the  work  where  the 
pieces  are  large  or  complicated  so  that  they  cannot  be  held  in  a 
vise  or  easily  clamped  to  the  table — (it  takes  skill  to  lay  out  and 
block  up  work  on  any  machine).  A  suitable  fixture  makes  it 
possible  to  use  less  skilled  workmen. 

Third:  Well-designed  cutters,  and  a  good  cutter-grinder  to 
keep  them  sharp. 

THE   MILLING-MACHINE   IN   THE   TOOL-EOOM. 

The  fate  of  many  a  manufacturing  concern  rests  with  its  tool- 
room, for  here  are  produced  the  jigs,  dies,  fixtures,  boring-tools, 
reamers,  etc.,  suitable  for  the  specialties  manufactured. 

Do  not  consider  it  a  necessary  evil  because  it  is  classed  as 
non-productive,  for  it  is  the  equipment  of  well -designed,  well- 
made  tools  that  enables  machine  tools,  standard  and  special,  to 
come  up  to  their  highest  efficiency,  and  place  the  factory  in  the 
fore-front. 

The  machine-tool  equipment  should  be  all  that  would  be  re- 
quired to  make  a  complete  high-class  small  machine-shop,  and 
the  tool-making  should  be  confined  to  it  as  far  as  possible  rather 
than  break  up  machines  engaged  in  manufacturing. 

MILLING   AN   ANGLE-PLATE. 

Here  the  universal  milling-machine  is  at  home,  provided  it 
is  a  first-class  machine  and  equipped  with  vertical-spindle  and 


126 


TOOL-MAKING   AND 


rack-cutting  attachment.  A  machine  of  this  kind  will  have  the 
greatest  possible  accuracy,  convenience,  and  range,  and  will  be 
found  adapted  to  every  variety  of  tool-room  work.  A  long  auto- 
matic cross-range  on  a  miller  is  also  desirable,  as  it  makes  it  an 
excellent  tool  for  accurate  jig-boring.  Fig.  119  shows  an  angle- 
plate  used  on  the  face-plate  of  an  engine-lathe  for  accurately 
boring  a  complicated  piece  that  has  two  holes  at  right  angles  to 
each  other.  The  angle-plate  was  first  milled  on  the  edge  in 
order  to   provide  a  surface  that  would  set  square  on  the  work- 


Fiu.  119. 

table.  The  hole  on  the  back  for  the  lathe-spindle  plug  was  first 
bored,  and  the  plate  shifted  to  the  position  shown.  It  is  obvi- 
ous that  these  two  holes  will  be  exactly  the  same  height  from  the 
edge  of  the  plate,  and  the  work  when  placed  upon  it  will  be  in 
line  with  the  lathe-spindle.  If  the  piece  had  been  a  box-jig,  a 
long  boring-bar  would  have  been  used  and  the  outer  end  sup- 
ported in  the  overhanging  arm.  Usually  it  is  better  to  make 
boring -bars  to  fit  in  the  taper  hole  in  the  spindle,  as  the  chuck 
takes  up  some  room.  The  Chuck  method,  however,  is  very  con- 
venient, as  the  boring-tool  need  be  only  a  straight  piece. 


INTERCHANGEABLE  MANUFACTURING.         127 


CIECULAE  JIG-MAKING   ON  THE  MILLER. 

It  often  happens  that  an  accurate  circular-jig  is  required  so 
that  the  two  pieces  drilled  will  fit  without  matching  holes.  This 
can  be  quickly  done,  as  shown  in  Fig.  120.     Note  that  the  divid- 


FIG.  120. 

ing-head  has  cross-slot  and  side-ears  so  that  blocking  and  strap- 
ping are  unnecessary,  and  the  large  dividing-wheel  insures 
accuracy. 

VERTICAL-SPINDLE   MILLING-MACHINES. 

In  establishments  where  large  numbers  of  machines,  appli- 
ances, and  parts  of  standard  shape  are  produced,  the  chief  desire 
is  the  increasing  of  .the  daily  output  without  increasing  the  labor 
cost.  This  desire  can  only  be  gratified  satisfactorily  by  using 
machines  which  can  be  kept  constantly  producing  parts  of  the 
same  shape  and  size.  It  is  in  shops  of  this  class  that  the  vertical- 
spindle  milling-machine  can  be  used  to  the  best  advantage  for  all 
work  that  can  be  produced  economically  by  vertical  milling. 

As  much  time,  skill,  and  money  have  been  expended  in  the 
development  of  this  type  of  miller,  the  advantages  to  be  gained 
through  its  use  are  numerous,  and  are  now  almost  universally 
recognized  where  economic  production  is  imperative.  The  util- 
ity of  vertical  millers  for  machining  surfaces  and  parts,  once 
only  thought  possible  to  do  on  the  lathe  or  on  the  planer,  is 
steadily  progressing,  as  the  degree  of  precision  to  which  the 
machine  has  been  developed,  namely,  permanency  of  alignment 
of  the  spindle  with  the  platen,  makes  the  production  of  accu- 
rate and  intricate  parts  by  its  use  assured.    . 


128  TOOL-MAKING  AND 

DOUBT   AS   TO   THE  UTILITY   OF   MILLING- 
MACHINES. 

To  those  who  are  in  doubt  about  the  utility  of  milling-ma- 
chines— plain,  universal,  vertical,  and  those  in  combination  with 
other  machines — for  modern  manufacturing,  tool-making,  and 
machine- jobbing,  a  trip  of  inspection  through  the  establishments 
devoted  to  their  production  would  convince  them;  as  in  such 
shops  they  "  practise  what  they  preach  "  and  have  adopted  their 
own  machines  for  the  rapid  and  accurate  production  of  parts  of 
machines  of  the  same  kind  with  the  most  gratifying  results,  the 
machines  being  used  to  the  exclusion  of  all  other  machine  tools 
on  all  jobs  permissible.  Thus  in  those  shops  the  milling-ma- 
chine is  practically  self -producing,  and  stands  to-day  a  monu- 
ment to  the  ingenuity  and  skill  of  those  men  who  conceived  it 
and  developed  it  to  its  present  high  state  of  perfection. 


CHAPTER  IX. 

Simple  Milling  Fixtures. 

SIX  DISTINCT   TYPES   OF   SIMPLE  MILLING 
FIXTURES. 

Having  in  preceding  chapters  described  various  types  of 
fixtures  and  tools  suited  for  machining  different  grades  of  dupli- 
cate work  by  drilling,  I  will  now  turn  my  attention  to  milling 
fixtures;  and  will  devote  this  chapter  to  those  adapted  for 
machining  the  simpler  grades  of  work  in  which  no  great  accu- 
racy is  required,  but  which,  at  the  same  time,  it  is  necessary  to 
produce  to  a  certain  degree  of  interchangeability. 

In  the  construction  of  tools  and  fixtures  for  the  machining 
and  duplication  of  interchangeable  machine  parts  by  milling,  a 
number  of  obstacles  must  be  overcome  that  are  not  met  with  in 
the  fixtures  and  jigs  described  in  preceding  chapters.  There  are 
also,  of  course,  a  number  of  practical  points  in  their  design  and 
construction  which  are  absolutely  essential  to  their  successful 
operation ;  the  conditions  under  which  they  are  operated  being 
totally  different  from  those  under  which  drilling- jigs  and  fixtures 
are  used.  It  does  not  require  as  high-grade  skill  to  construct 
fixtures  for  accurate  milling  as  for  accurate  drilling,  yet  the 
designing  of  these  fixtures  entails  considerably 
more  thought  and  practical  ability,   to  give      r~[Bp~~-\  i 

satisfactory  results.  /^~~\    \    E?lfl 

In  Figs.  121,  122,  and  123,  are  illustrated      V    (®)    Ylll 
three  samples  of  work  milled  by  the  use  of  in-         ^v^_Qj    I 
expensive  fixtures  which  may  be  aptly  termed  B 

Fig.  Lsl. 

' l  emergency  fixtures. "    The  fixtures  are  shown 
in  124;  125,  and  126.     The  design  and  method  of  construction  are 
very  simple,  and  are  clearly  shown  in  the  illustrations.     The  fixt- 
ure for  milling  the  square  channel  at  B  B,  Fig.  121,  is  shown  in 
9  129 


130 


TOOL-MAKING   AND 


Fig.  122. 


1 

E 

> 

G         G 

Fig.  123. 


Fig.  124.  It  consists  of  a  square  plate  L,  of  f -inch  fiat  machine- 
steel,  finished  all  over;  of  the  central  locating-stud  J  screwed 
tightly  into  the  centre  of  the  plate ;  of  the 
end  locating-pin  K,  and  of  the  two  dowel- 
pins  II  which  coincide  with  two  holes 
drilled  and  reamed  to  size  in  one  of  the 
steel  jaws  of  the  miller- vise.  The  channel 
L  is  used  as  a  guide  for  the  cutter,  and  also 
as  a  gauge  for  the  depth  and  location  of 
the  cut  in  the  work.  This  fixture  is  located 
on  the  inside  of  the  vise-jaw  by  the  dowels 
1 1,  and  the  stud  J  is  entered  into  the  reamed 
hole  A  of  the  work,  and  one  side  of  the  rough- 
cast channel  B  set  against  the  locating-pin  K 
as  shown.  The  vise  is  then  closed  and  tight- 
ened against  the  work,  and  the  cutter  is  set 

to  enter  the  guide -chaunel  L  of  the  fixture,  so 
that  it  will  just  touch  the  bottom  of  it.  One  end 
of  the  work  is  then  milled;  then  the  work  is 
reversed  on  the  fixture,  so  that  the  finished 
channel  will  locate  against  the  stop-pin  R,  and 
the  other  end  is  finished. 

The  other  two  fixtures  shown  in  Figs.  125 
and  126  are  also  constructed  to  locate  on  the 
stationary  jaw  of  the  miller - 
vise.  That  shown  in  Fig.  125 
is  relatively  the  same  as  the  first,  except  that 
no  stop-pin  is  required — the  work,  Fig.  122, 
being  round  and  having  but  one  slot,  D, 
milled  in  the  position  shown.  The  hubs  of 
the  work  are  faced  and  the  hole  G  is  reamed 
to  size,  the  outside  being  finished  to  a  given 
diameter  in  the  lathe  before  milling.  Fig. 
126  shows  a  fixture  used  for  milling  the 
channel  in  the  face  of  Fig.  123.  The  two  sec- 
tions are  of  cast-iron.  The  largest  one,  Q,  has  a  raised  projec- 
tion at  one  end,  with  a  guide-channel  B  milled  central  with  the 
V  on  the  face.     8  8  are  the  two  vise  jaw-dowels,  and  T  the 


Fig.  124. 


Fig.  125. 


INTERCHANGEABLE  MANUFA  CTUBING. 


131 


side  way  locating  pin  for  the  work.  Both  these  fixtures  are 
operated  in  the  same  manner  as  that  shown  in  Fig.  124,  and 
are  adaptable  for  milling  a  large  variety  of  small  machine  parts 
that  are  not  required  in  large  quantities,  or  in  which  a  given 
limit  of  error  is  allowed,  thus  necessitating  the  utmost  economy 
in  the  expense  of  the  fixtures  for  their  duplication.  The  efficiency 
and  practical  value  of  these  three  fixtures  are  at  once  apparent. 

FIXTUEES   FOE  MILLING   A   BEABING   IN   A 
BEACKET. 


A  plan  and  a  side  view  of   a  simple  fixture  that  can  be 
adapted  for  odd -shaped  castings   are  illustrated   in    Fig.   127. 
This  fixture  is  used  for  milling  the  bearing  and  cap -surface  of 
the    bracket,    Figs.    128    and 
129,  to  the  shape  shown  at  Y 
and  ZZ  respectively,  the  bear- 
ing Y  being  milled  to  an  ex- 
act half- circle  of  the   radius 
required,    so   as    to   conform 
with  its  duplicate  in  the  cap. 
This  is  afterward  fastened  to 
the  bracket  aud  the  bearing 

IS MS 


w^ 


V!W 


Fig.  126. 


Fig.  127. 


reamed  to  the  finish  size.  The  fixture  consists  of  one  main  cast- 
ing in  the  form  of  an  augle-plate.  When  the  base  has  been  fin- 
ished, the  tongue  J  fitted  to  the  central  slot  of  the  miller-table, 


132 


TOOL-MAKING   AND 


and  the  two  holes  drilled  for  the  fastening -bolts,  the  angle-plate 
is  set  up  on  the  miller,  facing  the  spindle.  The  face  is  then 
milled,  ending  in  a  square  shoulder  at  the  locating-surface  I. 
The  two  clamps  C  C  are  then  made,  and  holes  drilled  in  the 


FIG.  128. 


FIG.  129. 


face  of  the  angle-plate  to  admit  their  bolts  D  I).  Locating  set- 
screws  E  E  are  then  let  into  the  back  extension-lug  B  and 
fastening-screws  G  G  let  into  the  front  lug,  as  in  plan  view,  Fig. 
127.  Both  views  of  the  fixtures  show  clearly  the  manner  of  lo- 
cating and  fastening  the  work  on  the  fixture.  With  the  use  of 
this  fixture  one  can  rapidly  locate  and  fasten  the  work,  the 
clamping  arrangements  insuring  the  rigidity  of  the  work  when 
presented  to  the  cutter.  As  will  be  seen,  there  is  a  projecting 
surface  F  at  the  top  of  the  front  extension-lug ;  the  face  of  this 


FIG.  130. 

lug  is  milled  square  with  the  face  of  the  fixture,  and  acts  as  a 
gauge-point  for  setting  the  "gang  "  mill  the  proper  distance  from 
the  locating-face  of  the  fixture.  Fixtures  of  this  design  should 
be  used  wherever  possible,  as  the  small  number  of  parts  and 
rapid  handling  commend  them. 

FIXTUEE  FOR  USE   IN  SQUARING   THE  ENDS  OF 
DUPLICATE   PIECES. 

Fig.  131  gives  two  views  of  a  milling -fixture  which  is  (to  the 
best  of  my  knowledge)  new  in  design  and  has  possibilities  for  a 


INTERCHANGEABLE  MANUFA CTUBING. 


133 


wide  range  of  work  of  the  type  shown  in  Fig.  130.  This  work 
is  a  square -threaded  screw  with  duplicate  ends.  The  ends  were 
required  to  be  squared  so  as  to  be  exactly  in  line  with  each 
other,  as  shown  at  K  K.  The  fixture  is  made  to  accommodate 
six  screws  at  a  time,  and  is  made  in  two  sections,  Fig.  131. 
These  sections  are  of  cast-iron,  finished  and  squared  all  over, 
and  doweled  together  by  pins  Q  Q,  one  at  either  end.  The  spac- 
ing, locating,  and  finishing  of  the  six  work-receivers,  two  of 
which  are  shown  with  the  work  N Niu  position,  is  accomplished 
in  the  milling-machine  by  means  of  a  special  counter-gore.  This 
finishes  them  so  that  a  perfect  half -form  remains  in  each  section, 


Fig.  131. 


with  the  shoulder  of  each  at  0  exactly  the  same  distance  from 
the  top  of  the  sections.  A  cut  is  then  taken  off  the  face  of  each 
section  so  that  the  work  may  be  clamped  securely.  The  most 
interesting  feature  of  this  fixture  is  the  manner  of  locating  the 
work  within  it  so  that  the  second  operation  of  squaring  the  ends 
will  be  accomplished  with  ease  and  expedition.  This  is  done  by 
milling  a  slot  crosswise  through  the  bottom  of  the  sections  at  the 
side  of  each  receiver  to  accommodate  the  locating -plates  P  P  P  P 
P  P  as  shown.  These  slots,  or  channels,  are  so  finished  by  the 
use  of  the  graduate-dials  on  the  table  feed-screw. of  the  universal 
miller  that  when  the  plates  P  are  driven  tightly  into  one  of  the 
sections,  and  extending  into  the  other  (the  slots  in  which  must 


134 


TOOL-MAKING   AND 


be  slightly  enlarged  to  allow  of  their  entering  freely),  one  of  the 
squared  sides  of  the  end  of  the  work  milled  with  a  gang-cutter 
in  the  first  operation  will  rest  squarely  against  them.  When  in 
use  the  six  plates  P  are  first  removed  and  the  two  sides  of  one 
end  of  the  work  milled  with  a  gang-cutter.  When  all  have  been 
treated  in  this  manner  the  six  locating-plates  Pare  again  inserted 
in  their  channels  and  the  ends  finished;  requiring  three  opera- 
tions, as  follows :  First,  enter  the  ends  of  the  screws  that  have 
been  milled,  so  that  one  of  the  sides  rests  squarely  against  the 
locating-plate ;  then  mill  two  sides  of  the  other  end  at  right 
angles  with  those  milled  on  the  first  end.     Now,  by  reversing  the 


,, 


FIG.  132. 

screws,  the  remaining  two  sides  of  the  first  end  can  be  finished 
square  with  the  other  two.  This  operation  is  repeated  and  the 
ends  again  reversed,  thereby  finishing  both  ends  square  and  ex- 
actly in  line  with  each  other.  The  use  of  this  fixture  enables 
duplicate  parts  of  the  work  to  be  finished  exactly  alike,  and, 
what  is  more,  the  squaring  of  the  ends,  which  is  usually  a  slow 
and  difficult  job,  is  thus  accomplished  with  ease  and  rapidity. 

FIXTURES    FOR    USE    IX    SLOTTING    AND    DOVE- 
TAILING SMALL   PIECES. 

Two  examples  of  a  somewhat  different  type  of  milling  fixture 
are  illustrated  in  Figs.  133  and  134.  These  fixtures  are  used  for 
milling  the  casting  shown  in  two  views  in  Fig.  132,  and  embody 


INTERCHANGEABLE  MANUFACTURING. 


135 


in  their  design  and  construction  a  number  of  practical  points 
which  are  suggestive. 

That  shown  in  the  two  views  of  Fig.  133  is  used  to  mill  the 
square  channel  at  E  and  the  slot  D,  Fig.  132.  The  drawings 
clearly  show  the  method  of  construction.  The  work  is  located 
centrally  on  the  stud  K,  and  sidewise  against  the  stop -pin  N,  the 
clamp  I*  holding  it  tightly  and  securely  against  the  face  of  the 


Fig.  133. 


angle-plate  J.  The  guide-channels  M  M  M  M  are  for  the  large 
cutters,  and  LLL  L  for  the  slotting-cutters.  The  angle-plate,  or 
fixture  proper,  is  well  ribbed  at  the  back,  as  shown  at  Q  Q  Q, 
and  is  located  true  on  the  miller-table  by  a  "feather"  in  the 
channel  cut  in  the  bottom.  When  used  in  conjunction  with  a 
set  of  gang-mills  this  fixture  is  a  very  rapid  and  accurate  pro- 
ducer. The  guide -channels  in  the  fixture  enable  one  to  set  the 
cutters  to  take  the  proper  depth  of  cut  and  to  locate  them  cen- 


136 


TOOL-MAKING   AND 


tral  with  the  hole  B  in  the  work,  Fig.  132.  When  in  operation 
the  cut  is  against  the  fixture,  thereby  holding  the  work  rigidly 
against  its  face. 

Fig.  134  shows  two  views  of  a  fixture  whim,  although  very 
simple  and  inexpensive  to  construct,  has  much  to  commend  it. 
It  is  used  for  milling  the  dovetail  in  the  end  of  the  casting 
shown  in  Fig.  132,  and  will  accommodate  six  castings  at  a  time. 
It  consists  of  the  two  end  angle-brackets  B  B,  the  central  locat- 
ing- and  clamping-arbor  C,  and  the  locating-bar  0.     The  end- 


FIG.  134. 

brackets  B  B  are  first  bored  out  and  the  hubs  faced,  and  then 
they  are  placed  on  an  arbor  and  the  base  of  each  is  milled  with 
the  tongues  E  E  in  line~with  each  other.  A  square  hole  is  now 
let  into  the  face  of  each  bracket  at  F  as  shown,  and  finished  to 
size  and  in  line  by  clamping  both  brackets  together  and  forcing 
a  broach  through  the  unfinished  holes.  The  locating-bar  G  is  of 
square  tool  steel,  finished  all  over  for  its  entire  length,  to  fit 
nicely  within  the  holes  in  the  face  of  the  brackets.  The  width 
of  the  bar  is  made  to  fit  the  square  channel  E,  Fig.  132,  previ- 
ously milled  in  the  castings  or  work.     When  the  fixture  is  in  use 


INTERCHANGEABLE  MANUFACTURING. 


137 


the  bracket  B  at  the  right  is  clamped  securely  on  the  miller- 
table,  and  the  one  at  the  left  slipped  off  the  arbor  C.  The  six 
castings  I  are  then  slipped  on  to  the  arbor  with  the  square  milled 
channel  of  each  down,  so  that  the  locating-bar  G  rests  within 
them.  The  left  bracket  is  then  slipped  on  and  the  nut  K  tight- 
ened slightly.  By  tightening  the  screws  in  the  ends  J  of  the 
casting,  the  channels  are  clamped  to  the  locating-bar  G.     Nut  II 


Fig.  135. 

is  then  tightened  securely  and  the  bracket  firmly  clamped  to  the 
table:  By  the  use  of  the  vertical  attachment  and  of  an  angular 
cutter,  the  six  castings  are  milled  and  finished  to  the  shape 
shown  at  jF,  Fig.  132,  and  at  K,  Fig.  134. 

The  points  to  be  considered  when  designing  fixtures  for  mill- 
ing in  one  operation  a  number  of  small  parts  of  the  type  here 
shown  are  as  follows :  First,  the  number  which  can  be  handled 


138 


TOOL-MAKING   AND 


to  the  best  advantage;  second,  the  manner  of  presenting  the 
work  to  the  cutters,  and,  lastly,  the  most  expeditious  and  relia- 
ble means  for  locating  and  holding  the  work  rigidly  while  being 
milled. 

FIXTURE  FOR   USE  IN  GANG-MILLING. 

A  type  of  fixture  used  extensively  for  gang-milling,  where 
wide  surfaces  or  a  number  of  depressions  are  to  be  milled  in  the 
face  of  castings  that  have  not  been  previously  machined,  is  shown 


T 


t mi 

111-  Ft- 


UU~~h 


^Q^-^Q^ 


in  Figs.  135  and  136.  Although  of  the  simplest  construction,  it 
represents  a  useful  type  of  milling  fixture  for  the  milling  of  a 
large  variety  of  work  that  it  would  be  difficult  to  machine  rap- 
idly by  any  other  means.     This  fixture  is  used  for  the  milling  of 


H      H 


H       H 


Fig.  137. 


the  type  of  casting  shown  at  H,  Fig.  137,  which  consists  of  four 
channels  H  H  H  H  in  the  face,  and  of  the  square  channel  I  in 
one  end ;  requiring  two  separate  operations ;  both  being  accom- 


INTERCHANGEABLE  MANUFACTURING. 


139 


plished  on  the  one  fixture.  Fig.  135  shows  a  section  of  the 
plan  and  side  view,  and  also  an  end  view  of  this  fixture  which 
handled  eight  castings  at  once.  It  consists  of  one  large  casting  M 
having  two  half-round  depressions  running  down  its  entire 
length  as  clearance  for  the  projections  on  the  back  of  the  work. 
The  top  is  planed  true  with  the  base  as  a  squaring  surface  for 
the  work,  and  ends  in  a  square  shoulder  at  N  for  the  work  to 
locate  against.  The  work  is  held  in  position  by  clamps  at  R  R 
so  placed  as  to  clamp  two  castings,  as  shown  at  P  P.  The  holes 
for  the- bolts  are  counterbored  at  the  back  to  allow  the  heads  to 
clear  the  miller-table,  as  at  T  T  in  the  side  view,  Fig.  135.  The 
work  is  fastened  as  shown,  and  the  square  channel  in  the  end  is 
milled.  When  all  the  castings  have  gone  through  this  operation, 
the  four  channels  are  finished  by  relocating  and  fastening  the 
work  to  the  fixture  and  setting  a  gang  of  mills.  The  cross-slide 
of  the  miller-table  is  then  clamped,  the  depth  of  the  cut  set,  and 
the  castings  finished. 

FIXTUEE   USED   m   FACE-MILLING. 

Another  type  of  simple  milling-fixture  is  shown  in  the  two 
views  of  Fig.  138.     Although  somewhat  similar  to  that  shown  in 


FIG.  138. 


Fig.  135  it  is  used  for  a  distinctly  different  class  of  milling ; 
that  is,  face-milling.     The  sketch  shows  it  being  used  for  ends  V 


140 


TOOL-MAKING. 


V  of  castings  like  Fig.  139.  This  casting  is  first  set  up  on  the 
planer  and  the  dovetailed  slide-surfaces  U  U  are  planed  to 
gauge.  The  fixture  is  constructed  to  handle  two  castings  at 
once,  they  being  located  side  wise  by  forcing  the  side  of  one  of 
the  dovetailed  surfaces  Z  against  the  angular-faced  locating-lugs 
X  X  X  X  as  shown,  and  endwise  against  the  squared  and 
faced  projections  Y  Fat  the  back.  The  castings  are  held  in  po- 
sition by  two  clamps  each,  as  at  C  C  C  0,  and  the  heads  of  the 
bolts  are  let  into  the  base,  as  at  A  A  in  the  side  view.  The  ends 
of  the  castings  are  faced  by  a  large  cutter-holder,  with  self -hard  - 


FlG.  139. 


ening  steel  cutters  set  into  the  rim,  so  that  a  roughing  and  finish- 
ing cut  can  be  taken  at  the  same  time.  When  one  end  of  the 
casting  has  been  faced,  they  are  reversed,  relocated,  and  the 
other  ends  are  faced. 

When  the  large  variety  of  machine  parts,  both  small  and 
large,  which  can  be  machined  in  exact  duplication  of  each  other 
by  the  use  of  just  such  simple  and  inexpensive  fixtures  as  are 
here  shown  is  considered,  it  is  surprising  that  these  methods  of 
manufacture  had  not  been  adopted  more  extensively.  By  this 
we  mean  in  the  small  shop ;  for  in  the  large  shops,  unless  the 
machines  or  appliances  are  manufactured  under  patents,  it  is 
absolutely  necessary  to  manufacture  by  the  interchangeable  sys- 
tem in  order  to  meet  competition. 


CHAPTER  X. 

Milling-Fixtures  for  Accurate  Work. 

FACTORS    m    THE    SUCCESSFUL   USE   OF   ACCURATE 
MILLING-FIXTURES. 

We  are  now  about  to  take  up  a  class  of  milling-fixtures  of  a 
different  type  from  those  described  in  the  preceding  chapter,  in 
that  they  are  more  intricate  and  are  also  capable  of  producing 
more  accurate  results.  When  designing  these  tools  there  are 
three  questions  to  be  considered :  First,  are  the  parts  which  are* 
to  be  machined  required  in  large  quantities?  Second,  must  they 
be  finished  very  accurately,  so  as  to  be  interchangeable  ?  Lastly, 
can  the  parts  be  handled  and  finished  to  the  best  advantage  in 
the  milling-machine? 

The  first  two  questions  can  be  answered  in  very  short  order. 
But  in  deciding  the  answer  to  the  last  one,  the  knowledge  and 
skill  of  the  designer,  who  is  often  the  constructor  as  well,  are  put 
to  the  test.  If  it  is  decided  that  the  milling-machine  is  most 
suitable  for  the  work,  the  following  points  must  then  be  consid- 
ered after  the  shape  and  type  of  fixture  have  been  determined: 
The  surface  by  which  the  pieces  are  to  be  located ;  the  devices 
for  fastening  the  work,  and  the  most  practical  way  of  presenting 
the  surface  to  be  machined  to  the  cutter  or  cutters,  as  the  case 
may  be. 

As  types  of  the  most  reliable  class  of  milling-machine  fixtures 
for  duplicating  small  and  medium  machine  parts,  there  are  here 
shown  five  examples  which  are  well  designed  for  the  particular 
pieces  of  work  for  which  they  are  intended.  The  devices  also 
are  suggestive,  in  that  many  of  their  features  can  be  so  modified 
as  to  be  applicable  to  work  of  other  kinds.  Methods  for  con- 
structing the  fixtures  will  be  described — explaining  how  they 
can  be  produced  within  a  reasonable  length  of  time  and  at  mod- 
erate expense. 

141 


142 


TOOL-MAKING   AND 


FIXTUBE   FOR  THE   FIRST   PIECE   OF   WORK. 

The  fixture  shown  in  three  views  of  Fig.  140  is  used  for  fac- 
ing the  flat  surface  of  the  work,  Fig.  141.  The  finishing  of  the 
ends  of  the  piece  is  accomplished  in  the  lathe,  the  parts  e  e,  d  d, 
and  the  threaded  portions  being  interchangeable.  The  fixture, 
Fig.  140,  for  facing  the  flat  surface  F  true  with  the  turned  por- 


no. 140. 


tions  of  the  work,  is  of  few  parts,  and  holds  the  work  rigidly. 
As  the  method  of  construction  is  not  very  intricate,  and  can 
be  understood  from  the  illustrations,  a  slight  description  will 
suffice. 

The  fixture  proper  consists  of  the  body  castings  G,  the  stand- 
ards H  between  which  the  work  is  located,  the  back  projection 
I  for  the  fastening-  and  locating-screws  N  N  and  0  0  respec- 
tively, and  the  two  clamping-lids  J  J.  The  lid  clamping -screws 
L  L  are  fastened  in  the  slot  in  the  standards,  as  shown  in  the  face 
view,  by  means  of  Stub  steel  pins,  so  that  they  may  be  fastened 
and  released  as  rapidly  as  possible.  The  lids  J  J  are  hinged  as 
shown  at  K  K.  The  locating-screws  are  of  tool  steel  and  are  re- 
duced at  the  ends  as  shown  at  P,  in  the  end  Adew,  and  hardened 


INTERCHANGEABLE  MANTJFA CTTJRING. 


143 


and  equipped  with  jam-nuts.  The  tongue  T  is  let  into  a  slot  in 
the  body  casting  G  so  as  to  be  perfectly  in  line  with  the  turned 
portion  of  the  work  when  within  the  fixture. 

The  boring  of  the  standards  and  lids  to  size,  and  the  facing 
of  the  surfaces  M  M  so  that  the    work  will  fit  between  them 


FIG.  141. 

snugly,  is  accomplished  in  the  following  manner :  The  base  is 
first  planed  and  the  body  casting  strapped  to  an  angle-plate  on 
the  drill-press  table.  A  boring-bar  is  then  used  with  the  end 
running  in  the  bushing  in  the  table,  and  the  holes  are  bored  and 
the  shoulders  faced.  The  two  screws  N  N  for  forcing  the  work 
against  the  two  locating-screws  0  0  have  knurled  heads  with  a 
spanner  hole  as  shown,  are  threaded  to  screw  freely  in  the 
tapped  holes,  and  are  also  equipped  with  jam-nuts. 

When  using  this  fixture  it  is  clamped  on  the  miller-table  with 
the  tongue  T  in  the  slot  nearest  the  spindle.     The  two  lids  J  J 


\  m  f  P 


Fig.  143. 


FIG.  143. 


are  then  thrown  back  and  the  work  located  as  shown,  first  tight- 
ening the  lids,  and  then  forcing  the  work  against  the  two  locat- 
ing screws  0  0  by  means  of  the  knurled  head-screw  NN,  and 
fastening  the  nuts  to  keep  them  tightly  against  the  work.  The 
cross-feed  of  the  miller-table  is  then  clamped  so  that  the  cutter 


144  TOOL-MAKING   AND 

will  remove  the  amount  of  stock  required ;  and  the  face  is  milled, 
using  a  large  face-cutter,  running  it  so  that  the  cut  will  be  down- 
ward, thereby  taking  the  strain  off  the  fastening-screws  N  N  and 
keeping  the  work  against  the  locating-screws  0  0.  The  facing 
of  work  of  this  class  in  fixtures  of  the  type  shown  can  be  accom- 
plished to  a  greater  degree  of  interchangeability  and  in  less  time 
than  by  any  other  means  known  to  the  author. 

FIXTURE  FOR   USE  IN  MILLING  THE   SECOND   PIECE. 

In  Figs.  142  and  143  we  have  a  milling  fixture  of  a  more  in- 
tricate type,  and  one  which  for  rapid  locating,  fastening,  and 
releasing  of  the  work  when  finished,  would  be  hard  to  beat,  as 
one  turn  of  the  screw  fastens  or  releases,  as  required. 
This  fixture  is  constructed  for  the  accommodation 
[d  of  two  pieces  at  a  time,  and  could,  if  required,  be 
constructed  for  twelve  on  the  same  principle.  The 
fixture  was  designed  for  milling  work  of  the  shape 
shown  in  Fig.  144.  The  piece  was  of  machine  steel 
and  was  finished,  all  but  the  milling,  in  the  turret- 
lathe,  and  was  used  as  a  part  of  an  electric  cloth- 
cutting  machine  which  was  being  manufactured  in  large  numbers. 
The  milling  consists  of  a  slot  through  the  stem  at  a  and  a  flat  at 
either  side  of  the  largest  circular  portion,  as  shown  at  b  b. 

The  fixture  consists  of  two  castings,  P  and  E,  and  spring- 
chuck  devices,  of  which  J  J  are  tool-steel  pieces,  screwing  into 
the  casting  E  and  carrying  the  spring- jaws  K.  These  jaws  are 
forced  out  against  the  work  by  the  expanders  L  L,  which  screw 
into  threaded  holes  in  1 1.  The  one  point  in  the  construction  of 
this  fixture  most  worthy  of  a  detailed  description  is  the  manner 
of  finishing  the  locating -depressions  F  F  in  the  part  E.  This 
part  is  of  cast-iron,  with  a  projecting  lug  at  M  which  is  used 
when  finished  as  a  gauge  for  setting  the  three  cutters  which  mill 
the  work.  This  cast-iron  block  is  first  planed  on  all  sides,  and 
one  side  N  finished  dovetail,  to  fit  tightly  into  the  dovetailed 
channel  milled  in  the  body  casting  P.  This  channel,  by  the 
way,  was  milled  on  the  front  of  the  casting  and  faced,  after  the 
base  had  been  finished  and  the  groove  for  the  tongue  was  milled, 


INTERCHANGEABLE  MANUFA CTURING. 


145 


on  the  machine  on  which  the  fixture  was  to  be  used,  to  guard 
against  inaccuracy. 

The  block  E  was  driven  into  this  channel  and  fastened  by- 
two  screws,  shown  at  F.  The  position  of  the  centres  for  the  lo- 
cating-depressions  FFFF  were  then  located  so  as  to  be  dead 
in  line  with  each  other  by  the  "button"  method  described  in 
a  previous  chapter.  The  depressions  were  finished  and  holes 
bored  and  threaded  at  the  back  by  strapping  the  block  E  on  the 
lathe  face-plate,  truing  the  "buttons," boring  the  holes,  finishing 
the  formed  depression  to  exactly  the  shape  and  depth  by  means 
of  a  forming-tool,  and  then  reversing  the  work  and  enlarging  and 
finishing  the  holes  at  the  back,  as  shown. 

When  the  fixture  is  in  use,  the  work  is  held  down  on  the  lo- 
cating-face  F  F  by  hand,  and  the  expander  given  a  turn  by  the 
handle  J.  This  causes  the  spring-chuck  K  to  grip  the  work  and 
draw  it  down  on  the  locating -face.  The  cutters  are  then  set  by 
the  gauge  M  and  the  work  milled. 

DESCRIPTION   OF   FIXTURE   FOE   THE   THIRD   PIECE. 


In  Fig.  145  there  are  two  views  of  a  piece  which  is  an  ideal 
job  for  the  milling-machine.  It  is  a  cast-iron  spindle-bracket, 
and  the  milling  operation  consisted  of  facing  the  fronts  and 
backs  of  the  two  bosses,  and  finish- 
ing the  projecting  rib  H  at  a  cer- 
tain distance  from  centre  of  hole 
Q  and  at  a  right  angle  with  the 
hole  K.  Before  milling,  the  hole 
Q  is  bored  and  one  side  of  the  hub 
faced  in  the  turret-lathe.  The  op- 
posite side  is  then  faced  and  the 
two   holes  drilled  through  g  g  and  FlG'  U-' 

one  through  K.     The  side  j  is  faced  in  a  special  jig  and  all 
points  machined  are  interchangeable. 

The  milling  fixture  shown  in  Figs.  146-147  is  designed  to 

hold  two  pieces  of  work  at  once,  and  can  be  constructed  for  the 

accommodation  of  a  dozen,  if  desired.     One  casting,  A,  is  all  that 

is  required  for  this  fixture,  and  is  in  the  shape  of  an  angle-plate 
10 


146 


TOOL-MAKING   AMD 


with  projecting  bosses  at  the  front  and  back  at  B  B  as  surfacing  - 
points  for  the  work,  and  four  projecting  lugs  on  the  face,  of 
which  E  E  are  for  the  locating-points  and  D  D  for  the  fasten- 
ing screws.     For  clamping  the  work  in  position  a  device  is  used 


SECTIONAL  VIEW,  LOOKING  AT  LEFT  END  OF  FRONT  VIEW* 
'  MOWN  0ELOW 


FIG.  146. 


which  allows  the  work  to  be  fastened  or  removed  with  the  great- 
est rapidity.  It  is  shown  clearly  in  the  sectional  view  of  the 
fixture,  and  consists  of  a  stud  M  of  tool  steel,  which  is  turned  to 
fit  nicely  the  hole  J  in  the  work  and  L  in  the  fixture.     It  is  of 


lnJu=tMI  P.t\t,  S.fJ 


Fig.  147. 


the  same  diameter  for  its  entire  length  and  is  threaded  at  the  end 
P  for  the  nut  8  and  reduced  as  shown  in  JV  to  admit  the  clamp- 
ing-washer Q.  This  washer  is  of  tool  steel  and  is  knurled  on  the 
outside  so  it  can  be  easily  removed,  and  has  a  section  cut  out  as 


INTERCHANGEABLE  MANUFACTURING.         147 

shown,  for  slipping  it  into  the  reduced  channel  N  of  the  stud  M. 
The  locating-faces  of  the  lugs  E  E  are  faced  at  right  angles  with 
the  stud  N,  so  that  when  the  faced  portion  J  of  the  work  is 
forced  against  the  locating-face  it  will  rest  perfectly  fiat  and 
bear  all  over.  The  fastening-screws  U  U  are  reduced  at  the 
ends  W  W,  ending  in  a  square  for  the  washers  V  V.  The  head 
of  the  clamping-stud  M  is  milled  with  a  flat  on  two  sides  for  a 
wrench. 

When  in  use,  the  fixture  is  clamped  to  the  miller-table  with 
the  tongue  C  in  the  central  slot.  The  nuts  P  of  the  clamping - 
studs  are  then  loosened,  the  work  slipped  on  as  shown,  the 
clamping -washer  Q  Q  located,  and  the  nuts  P  tightened  by  using 
wrenches  on  them  and  on  the  end  0  0  of  the  studs.  The  work 
is  then  forced  against  the  locating-lugs  E  E  by  the  set-screws 
U  U  and  milled,  as  shown,  by  setting  a  pair  of  straddle-mills 
for  the  proper  depth  of  cut  and  clamping  the  cross-feed  of  the 
miller-table.  To  remove  the  work  all  that  is  required  is  to  loosen 
the  set-screw  U  U  and  the  nuts  P,  slip  off  the  washers  Q  Q,  and 
remove  the  work.  The  rapidity  with  which  this  fixture  can  be 
operated  and  the  perfect  interchangeability  of  the  work  pro- 
duced is  surprising.  The  device  shown  for  clamping  the  work 
is  far  superior  to  the  usual  methods  adopted. 

INDEXING   MILLING   FIXTURES   FOR   LAST   TWO 

PIECES. 

As  there  are  a  large  variety  of  circular-shaped  machine  parts 
to  be  milled  at  different  points  regularly  spaced,  I  show  in  the 
last  two  illustrations  two  types  of  indexing  milling  fixtures  in 
which  simple  means  are  used  for  the  attainment  of  the  results 
indicated  in  the  sketches  of  pieces  shown  in  Figs.  148  and  149. 
The  first  of  the  two  fixtures,  the  one  shown  in  two  views  in  Fig. 
150,  is  used  for  milling  the  six  equally  spaced  channels  M  in  the 
disk,  Fig.  148.  The  castings  for  these  parts  are  finished  all  over 
in  the  turret-lathe  to  the  shape  shown,  and  are  then  milled  two 
at  a  time  on  the  fixture,  Fig.  150.  The  illustrations  show  a  plan 
and  cross-section  view  respectively ;  as  the  design  and  method 
of  construction  can  be  understood  from  them,  very  little  descrip- 


148 


TOOL-MAKING  AND 


tion  is  necessary.  A  is  the  fixture  proper,  the  work  being- 
located  centrally  on  the  studs  E  E,  which  are  let  into  the  base 
and  located  for  height  on  the  faced  surfaces  0  0  as  shown  in  the 
cross-section.  The  holes  in  which  the  studs  E  E  are  located  are 
bored  sufficiently  large  to  give  clearance  for  the  hubs  of  the 


FIG.  148. 


FIG.  H9. 


work,  as  shown  at  D.  The  high  projecting  lugs  B  B  B  B  are 
surfaced  so  as  to  allow  the  clamps  N  JST  JSf  JSf,  two  to  each  part, 
to  clamp  the  work  securely.  The  indexing  device  is  shown  in 
the  plan  view  and  is  self-explanatory.     The  projecting  lug  at  the 


FIG.  J 50. 

right  end  of  the  work  has  a  slot  milled  through  it  in  a  central 
line  with  the  central  locating -studs  E  E  and  to  the  depth  re- 
cpaired,  thus  serving  as  a  gauge  for  the  depth  of  cut. 

When  in  use  the  work  is  located  and  fastened  as  shown,  only 
that  the  indexing-pins  are   out.      A  cut  is  then   taken  down 


INTERCHANGEABLE  MANUFA GTURING. 


149 


through  both  parts,  as  shown  by  the  arrows,  to  XX.  The  table 
is  then  run  back,  the  clamps  slacked,  and  the  work  moved  until 
the  index-pins  H  H enter  the  channels  just  milled.  Tightening 
the  screw  J  of  each  to  hold  it  securely,  the  cutter  is  run  through 
again  and  the  operation  repeated.  The  work  is  then  removed 
by  loosening  the  clamp -bolts  0  and  sliding  the  clamp  back ; 
provision  being  made  for  this  by  slotting  the  bolt-holes  of  the 
clamps,  as  shown  at  Q  Q  in  the  cross-section.  By  changing  the 
location  of  the  indexing  device,  work  may  be  milled  with  any 
number  of  slots  or  grooves;  in  fact,  there  is  an  inexhaustible 
variety  of  work  for  which  fixtures  of  this  design  can  be  adopted 
with  the  best  results. 

Fig.  151  shows  two  views  of  a  fixture,  the  use  of  which  dem- 
onstrates how  work  usually  produced  in  jigs  on  the  drill -press 
may  be  machined  in  a  better  manner  by  the  use  of  simple  fixt- 


tig.  151. 


ures  on  the  milling-machine.  The  fixture  is  used  for  counter- 
boring  and  facing  the  six  bosses  of  the  spindle-disk  casting 
shown  in  two  views  in  Fig.  149.  The  points  previously  ma- 
chined are  the  hole  G,  the  six  holes  marked  P,  and  the  two  hubs, 
all  being  finished  to  interchange.  The  fixture  consists  of  the 
angle-plate  A,  which  has  a  projecting  hub  ou  either  side  at  I> 
and  B,  and  the  central  locating-stud  and  the  indexing-pin  0. 
After  the  angle- plate  is  planed  on  the  bottom  it  is  fastened  to 


150 


TOOL-MAKING  AND 


the  lathe  face-plate,  and  the  hub  D  faced.  A  hole  is  then  bored 
straight  through  the  centre  of  the  hubs  and  reamed  to  size,  and 
counterbored  to  the  diameter  and  depth  shown  in  the  sectional 
view,  for  clearance  for  the  hub  of  the  work.  It  is  then  trans- 
ferred to  the  planer,  where  the  hub  B  is  faced  and  the  channel 
let  in  for  the  tongue.  .  The  central  locating-stud  is  then  finished 


Fig.  152. 


so  as  to  shoulder  at  H,  and  reduced  and  threaded  at  the  back 
end  for  the  washer  Zand  the  jam -nuts  L  L,  so  as  to  revolve 
freely  without  play  within  the  fixture.  The  device  is  now  drilled 
for  the  two  hardened  steel  bushings,  one  at  B  for  the  index-pin 
0  and  one  diametrically  opposite  at  8.  To  properly  locate  these 
bushings,  the  work  is  fastened  on  the  central  stud  I  and  the 
hole  for  the  index-pin  bushing  R  is  finished,  first  by  drilling 
through  one  of  the  holes  P  in  the  work,  which  is  then  removed 
and  the  hole  counterbored  to  admit  the  bushing  B,  as  shown 
by  the  dotted  lines.  The  hole  through  the  bushing  is  lapped  to 
exactly  the  same  diameter  as  the  six  reamed  holes  P  in  the  work. 
The  index-pin  0  is  then  made  of  tools  teel — the  head  being 
knurled  as  shown — then  hardened  and  ground  to  fit  snugly 
within  the  reamed  holes  P  in  the  work  and  the  bushing  B  in 
the  fixture,  being  located  by  entering  index-pin  0  through 
one  of  the  holes  P  and  into  the  bushing  B ;  the  hole  for  bush- 
ing 8  is  finished,  and  the  bushing  entered  in  the  same  manner  as 
the  other. 

To  operate  the  fixture  the  work  is  fastened  as  shown,  and  the 
counterbore  located  in  a  taper-sleeve  in  the  miller-spindle. 
The  longitudinal  and  cross-feeds  of  the  table  are  then  manipu- 
lated until  the  lead  or  supporting  stud  of  the  counterbore, 
Fig.  152,  is  in  line  with  and  can  be  entered  into  the  bushing  8. 
The  work  is  then  fed  against  the  cutter  until  the  required  amount 
of  stock  has  been  removed,  and  the  graduated  dial  on  the  cross- 


INTERCHANGEABLE  MANUFACTURING.         151 

feed  screw  set  at  0.  The  table  is  then  moved  back,  index-pin 
O  removed,  and  the  work  revolved  one  space  or  until  the  next 
hole  P  is  in  line  with  the  bushing  R.  The  index-pin  is  then  re- 
entered and  the  operation  of  counterboring  and  facing  repeated, 
and  so  on  until  all  six  of  the  bosses  have  been  machined  in  repe- 
tition. 


CHAPTER  XL 

Miscellaneous   Milling    Fixtures,    and    Special   Tools 
for  Similar  Work. 

A   MILLING   FIXTUEE    FOE   DEILL-PEESS    TABLES. 


In  the  machining  of  tables  for  three-  and  four-spindle  sensi- 
tive drill -presses,  one  fixture  is  worthy  of  interest,  as  it  is  both 
simple  and  effective  for  the  accomplishment  of  the  work  desired. 
It  is  also  suggestive  for  other  work.  The  fixture  is  used  for  mill- 
ing the  dovetail  in  the  table  to  fit  the  slide-surface  of  the  base 
or  lower  column,  and  is  shown  in  two  views  in  Figs.  153-151. 


VERTICAL  MILLER 


It  is  used,  as  shown,  in  the  vertical  milling-machine.  The  table- 
surfaces  of  the  castings  were  first  planed  up,  after  which  they 
were  ready  to  be  milled.  The  fixture  consisted  of  one  casting 
JVT  in  the  shape  of  an  angle-plate.  This  casting  was  first  planed 
on  the  bottom  and  the  tongues  0  0  fitted  to  the  slot  in  the 

152 


INTERCHANGEABLE  MANUFACTURING.         153 


miller-table.  A  cut  was  then  taken  off  the  face,  getting  it  as 
true  and  smooth  as  possible,  as  the  face  of  the  table  located 
against  this  surface.  The  two  gauge-pieces  Q  and  R,  respec- 
tively, were  worked  out  and  fastened  to  the  angle-plate  with 
dowel-pins  and  screws,  so  they  would  serve  as  locating-points  for 
the  edges  and  face  of  the  table.  Three  holes  P  P  P  were 
drilled  in  the  base  of  the  angle-plate,  as  shown,  for  the  bolts 

w 


V— 


I 

.mi 


i 


p-o: 


o 


Is 

np 


LIMIT  GAUGE 


NOT  IN\ 

Fig.  154. 

used  in  fastening  it  to  the  milling -machine  table.  Holes  were 
also  drilled  and  tapped  in  the  face  for  the  strap -screws  T  T  T. 
Three  straps  were  then  made  of  machine  steel  and  bent  at  right 
angles  at  one  end,  finishing  them  so  as  to  be  in  the  position 
shown  when  clamping  the  table. 

The  fixture  was  then  set  up  and  clamped  to  the  miller-table, 
as  in  the  position  shown  in  the  top  view,  and  a  table  ready  to  be 
milled  stripped  to  it  as  shown,  resting  and  being  located  on  the 
top  pieces  Q  and  R  respectively.  A  screw-jack  was  then  used 
to  brace  the  extension  part  of  the  table  at  W,  thereby  taking  up 
the  downward  strain  on  the  table  while  the  dovetail  was  being 
milled.  The  milling  was  then  finished  in  two  cuts,  as  shown  at 
N  in  the  upper  view,  milling  it  to  fit  the  limit-gauge  shown  at 
the  bottom. 

The  use  of  this  fixture  gives  a.  practical  illustration  of  one  of 
the  various  kinds  of  work  for  which  the  vertical  milling-ma- 
chine is  adaptable,  as  the  operation  shown  can  be  accomplished 
in  one  quarter  the  time  which  it  would  take  to  do  on  the  planer, 


154 


TOOL-MAKING  AND 


or  on  the  regular  milling-machine — where,  in  milling  the  dove- 
tail, the  table  would  be  strapped  to  the  miller-table,  which  would 
have  to  be  raised  and  lowered  by  hand  while  milling,  which  is 
both  hard  on  the  operator  and  on  the  machine  as  well ;  as  will  be 
at  once  understood. 

JIG   FOFJ   MILLING  DBILL-PRESS   SPINDLE-HEADS. 


The  jigs  described  and  shown  in  the  following  were  used  for 
milling  and  boring  drill-press  spindle-heads  manufactured  by 
the  interchangeable  system,  and  are  both  reliable  and  cheap  in 
design  and  construction. 

The  spindle-head  is  shown  in  two  views  in  Fig.  155,  and  a 
slight  description  will  tend  to  the  intelligent  understanding  of 

the  requirements  and  construction 
of  the  jigs.  The  operations  on  the 
head  consisted  of,  first,  the  milling 
of  the  dovetailed  A  to  fit  the  column 
of  the  drill-press;  then  the  cutting 
out  of  the  two  lugs  R,  thereby  al- 
lowing sufficient  spring  in  the  spin- 
dle-head to  tighten  it  to  the  column.  The  hole  is  then  drilled  at 
G  for  the  clamping-lever.  After  this  is  done,  the  hole  D  is  bored 
and  finished.  This  hole  must  be  accurately  located,  as  the  pin- 
ion, when  inserted,  must  mesh  accurately  with  the  rack  on  the 


Fig.  155. 


TOP  VIEW 


JIG  FOB  MILLING,   DRILL  PRESS  SPINDLE  HEADS 


FIG.  156. 


spindle,  and  in  order  for  the  heads  to  interchange  the  jigs  must 
be  accurately  constructed.  When  casting  the  heads,  the  holes 
for  the  spindle  and  pinion  are  cored  sufficiently  small  to  allow 


INTERCHANGEABLE  MANUFACTURING.         155 

of  the  holes  being  finished  to  size,  in  case  of  a  slight  variation  in 
the  location  of  the  holes  when  cored  in  the  casting. 

The  jig  used  for  milling  the  dovetail  A  in  the  head  is  shown 
in  three  views  in  Figs.  156  and  157  respectively,  and  is  very 
simple  in  both  design  and  construction.  It  consists  of,  first,  a 
large  flat  casting  E,  for  which  a  pattern  of  the  size  and  shape 
shown  was  first  made,  and  stock  left 
sufficient  at  all  locating-points  to  al-  £ffl 

low  of  finishing.  After  a  casting  was 
secured,  it  was  first  set  up  on  the 
planer  and  the  back  planed  and  the 
tongues  G  G  fitted  to  the  central  slot 
of  the  table  of  the  large  milling-machine.  It  was  then 
placed  on  the  table  of  this  milling-machine,  and  clamped 
to  the  table  at  each  end,  H  H.  By  viewing  the  cross-section 
shown  in  Fig.  157  it  will  be  seen  that  the  head  is  located  at 
three  points  I,  J,  and  K.  The  point  I  is  milled  out,  as  shown, 
to  a  radius  approximately  the  same  as  that  portion  of  the  head 
which  rests  at  that  point,  as  shown.  The  points  J  and  K  are 
then  milled  so  that  the  head  will  rest  perfectly  parallel  on 
the  jig.  In  locating  castings  of  the  kind  shown,  the  clamping 
portion  must  be  located  at  the  strongest  point,  especially  in  this 
case,  as  the  milling  is  finished  in  two  cuts,  which  are  very  heavy 
cuts.  As  will  be  seen,  this  jig  is  made  to  accommodate  eight 
heads,  and  for  clamping  these,  four  studs  and  straps  are  re- 
quired ;  each  one  clamping  two  heads,  as  shown  at  M  M  31 M. 
The  studs  are  of  machine  steel,  turned  and  threaded  at  each  end 
and  screwed  tightly  into  holes  drilled  in  the  jig.  As  shown,  the 
straps  are  of  -§-inch  flat  machine  steel-,  cut  off  the  proper  length 
and  dressed  at  each  end  at  the  grinder.  The  nuts  H  are  faced 
upon  one  side  and  case-hardened.  When  all  parts  are  assem- 
bled as  shown,  and  the  eight  heads  strapped  and  located  in  posi- 
tion, an  angular  end-mill,  screwed  and  fastened  on  to  the  screw- 
arbor,  is  used  for  milling  them.  For  gauging  the  depth  of  cut, 
a  double-ended  gauge  of  f -inch  tool  steel  is  used,  one  end  to  go 
in  and  the  other  end  not  to  go  in.  For  gauging  the  distance 
from  the  centre  of  the  spindle  hole  to  the  faces  of  the  cutter,  a 
button-gauge  is  used,  the  bottom  fitting  the  spindle  hole  (which 


156 


TOOL-MAKING   AND 


is  rough)  freely,  and  the  piece  of  steel  in  which  it  is  fastened 
resting  on  the  table  of  the  miller.  The  distance  from  the  cutter 
to  the  other  end  of  the  gauge  being  correct,  the  work  is  fed  in 
until  the  face  of  the  cutter  just  touches  the  gauge;  the  cross- 
slide  of  the  table  is  then  clamped,  and  the  table  is  raised  or 
lowered,  as  may  be  required,  until  the  edge  of  the  cutter  rests  on 
a  slight  projection  on  the  end  of  the  gauge.  This  is  for  locating 
the  cut  approximately  central  with  the  spindle  hole.  The  mil- 
ler is  then  started,  and  the  cutter  allowed  to  run  through  the 
entire  eight  heads.  The  table  is  then  fed  back  to  the  starting 
point  and  raised  a  sufficient  number  of  thousands  until  the  small 
gauge  will  just  go  in.  The  cut  is  then  started  and  run  through, 
then  the  heads  are  removed  and  another  eight  located  and 
clamped.     The  operation  is  then  repeated. 

MACHINING  DRILL   COLUMNS. 

The  tools  here  shown  were  designed  by  the  author  and  used 
for  machining  the  upper  columns  of  small,  one-spindle  drill - 
presses.     The  column  is  shown  in  position  on  the  fixtures.     The 


Fig.  158. 


points  machined  are  the  finishing  of  the  slide-surface  A  A  for 
the  adjustable  spindle -head ;  the  milling  of  the  base  M  and  of 
the  baek  P,  as  shown ;  and,  lastly,  the  boring  of  the  hole  for 


INTERCHANGEABLE  MANUFACTURING.         157 

the  spindle  through  the  column  at  L  and  through  the  spindle- 
head. 

The  milling  of  the  slide-surface  is  done  first  in  order  to  have 
a  reliable  surface  by  which  to  locate  for  the  following  operations. 
The  body  of  the  fixture  is  a  long  casting,  B,  with  a  high  projec- 
tion at  each  end,  the  one  at  E  being  a 
"  V"  for  the  body  of  the  column,  and 
the  one  at  the  other  end  flat  and  square 
with  the  base,  for  the  head-supporting 
bracket  I.  This  bracket  is  of  cast- 
irou,  cored  out  at  J  so  that  the  head 

Fit;    159 

of  the  column  L  will  enter  it,  the  in- 
ner side  of  J  being  open  so  as  to  allow  of  this.  The  bracket 
is  fastened  to  the  body  casting  byfour  cap -screws.  A  feather 
C  is  let  into  each  end  in  a  channel  in  the  base  to  locate  it 
in  the  slot  of  the  miller-table,  and  it  is  fastened  by  bolts 
through  the  holes  at  D  D.  Two  clamps  at  Fand  G  are  used  to 
fasten  the  work ;  F  being  nearly  over  the  vertical  adjusting -screw 
N.  A  knurled  head-screw  at  H  forces  the  head  L  against  the 
locating  set-screw  K  in  the  face  of  the  bracket  I  and  the  two 
other  set-screws  E  act  vertically  as  locating-  and  fastening- 
screws. 

For  the  milling,  a  gang  of  cutters  and  a  special  arbor  of  the 
shape  shown  are  used,  the  angle  or  first  cutter  being  threaded 
with  a  left-hand  thread  to  screw  onto  the  arbor  and  force  the 
other  two  cutters  tightly  together.  The  narrow  cutter  is  to  finish 
a  flat  along  the  extreme  edge  of  the  milled  surface,  and  the  large 
one  is  for  milling  the  face.  The  last  two  cutters  are  keyed  to  the 
arbor. 

The  fixture  is  first  bolted  to  the  miller-table,  and  the  work  is 
fastened  upon  it,  adjusting  all  locatiDg-screws  so  that  approxi- 
mately the  same  amount  of  stock  can  be  removed  from  all  parts. 
As  the  variation  in  the  castings  is  very  little,  if  the  first  column 
has  been  machined  correctly  all  the  others  will  be.  A  gauge  is 
used  to  set  the  gang  of  mills.  The  work  is  moved  up  to  the  cut- 
ters until  the  face-cutter  is  removing  the  required  amount  of 
stock  and  the  angle-cutter  is  touching  the  gauge.  When  the  top 
is  finished,  the  table  is  raised  and  the  under  side  is  finished, 


158 


TOOL-MAKING  AND 


starting  at  D  D.  Before  this  fixture  was  designed,  the  finishing 
of  the  slide  A  A  was  done  on  the  planer ;  but  by  this  arrange- 
ment the  same  results  were  accomplished  in  one-third  the  time 
and  to  a  far  greater  degree  of  uniformity. 

For  facing  the  base  M  and  the  surface  P  the  fixture  shown 
in  Figs.  160-161  was  used.     This  was  made  for  three  columns, 


Fig.  160. 


only  one  of  which  is  shown.  The  dovetailed  slide -surface  pre- 
viously machined  is  utilized  for  locating  and  fastening  the 
columns.     The  fixture  consists  of  one  heavy  body  casting,  with 


Fig.  161. 

three  standards  on  which  the  work  is  fastened.  The  locating- 
surfaces  at  F  F  F,  respectively,  are  finished  on  the  planer,  one 
side  at  E  with  a  dovetail  at  the  same  angle  as  that  of  the  ma- 
chined surface.  Two  angular-faced  clamps  G  G,  with  clamp- 
screws  H,  are  used  for  fastening  each  column.  Two  straps  H  H 
are  also  used ;  although  they  are  not  absolutely  necessary. 


INTERCHANGEABLE  MANUFACTURING. 


159 


The  base  M  is  finished  first,  doing  the  entire  number  of  cast- 
ings.    They  are  then  reversed  on  the  fixture  and  the  backs  P  are 
faced  with  an  inserted  tooth-face  milling-cutter,  which  is  fast- 
ened in  the  vertical  attachment.     The 
same  cutter  is  used  for  facing  the  bases 
of  the  columns. 

The  boring -fixture  is  shown  in  Figs. 
162-163,  in  the  side  view  of  which  the 
work  is  shown  in  position,  with  the 
spindle-head  attached  to  the  slide- 
surface,  ready  to  be  bored.  The  boring 
and  finishing  of  the  spindle  hole  in  the 

head  L  of  the  column  and  in  the  spindle-head  at  one  and  the 
same  time  is  necessary  in   order  to  insure  the  alignment  of 


Fig.  162. 


§     i~Tj9G. 


C  L    |  N 


V 

J 

P/1 

l  : 

N 

(2P|, 

£& 


Fig.  163. 


those  holes.  This  fixture  is  rather  more  intricate  and  expen- 
sive than  the  two  preceding;  but  the  cost  was  approved  by 
the  result. 

The  fixture  is  in  the  form  of  a  tall  angle-plate,  with  two 
standards  N  projecting  from  the  inside  of  C  for  the  locating-  and 
fastening-points.  These  standards  are  cored  at  K,  as  shown  in 
the  end  view,  to  clear  the  boring-bar.     Bevel-faced  clamps  R  Rf 


160  TOOL-MAKING  AND 

with  clamp-screws  P  P,  secure  the  work.  There  were  two  bush- 
ings, one  at  the  top  in  D  at  E,  and  the  other  in  the  base  J  at  H. 
The  holes  for  these  bushings  were  cored  small  in  the  fixture 
when  cast,  and  were  bred  to  finish  size  on  the  large  drill-press  on 
which  the  fixture  was  to  be  used.  Before  boring  and  finishing 
these  holes,  the  other  locating-  and  lining-points  on  the  fixture 
were  finished,  and  the  piece  was  strengthened  by  fastening  two 
wide  and  stiff  machine-steel  straps  at  the  sides,  as  shown  at  S  8. 
These  straps  strengthened  the  fixture  considerably  and  insured 
its  rigidity. 

The  bushings  E  and  II  were  of  tool  steel,  hardened  and  lapped 
-to  a  good  fit  on  the  boring- bar,  and  then  ground  on  the  outside 
and  forced  into  their  respective  holes.  There  were  four  lugs  F 
with  hardened  set-screws  G  and  check-nuts  to  resist  side-thrust 
when  boring  the  holes  in  I  and  Q.  Large  openings  in  the  up- 
right at  b  b  and  c  c  were  convenient  for  inserting,  fastening,  and 
removing  the  cutters  from  the  boring- bar. 

The  fixture  rests  on  the  base  B  on  the  table  of  the  large  drill- 
press,  and  the  work  is  fastened  as  shown.  The  boring-bar  is 
then  slipped  down  through  the  bushings,  and  the  table  of  the 
drill-press  swung  around  until  the  shank  of  the  bar  can  be  driven 
up  into  the  drill-spindle.  The  roughing-cutters  are  fastened 
in  the  bar  and  fed  down  through  the  holes.  The  bar  is  then 
raised ;  the  roughing-cutters  are  removed ;  a  finishing  set  is  sub- 
stituted, and  the  holes  then  finished. 

The  boring  fixture  here  shown  was  used  only  for  machining 
single-spindle  columns;  for  the  two,  three,  four,  five,  and  six- 
spindle  frames  a  special  self -driven  machine,  that  might  be  set 
to  bore  two  columns  at  once,  was  used.  In  this  machine  the 
work  was  located  and  fastened  upon  it  in  the  same  way  as  here 
shown,  the  only  difference  being  in  the  driving  of  the  boring- 
bars  or  cutter- spindles  by  bevel-gears,  aud  feeding  them  through 
the  holes  in  the  work  by  a  pinion  and  rack,  in  relatively  the 
same  manner  as  on  a  self-feeding  drill-press. 

CHIEF   FACTOE   IX   MACHINE   MANUFACTURING. 

One  of  the  chief  factors  in  modern  manufacturing  of  machine 
parts  by  the  interchangeable  system  is  the  selection  of  the  proper 


INTERCHANGEABLE  MANUFACTURING.      -  161 

machines  and  tools  for  the  accomplishing  of  the  results  desired ; 
those  that  will  allow  of  the  rapid  machining  of  the  work  are,  of 
course,  the  ones  to  use.  It  is  a  common  sight  in  a  great  many 
manufacturing  machine-shops  to  see  work  being  laboriously 
performed  by  the  use  of  inadaptable  machines  and  tools,  which 
could,  by  the  use  of  a  machine  more  adaptable  for  it,  be  accom- 
plished with  ease  and  expediency.  In  fact,  I  have  often  seen 
machines  standing  idle  while  the  work  which  should  have  been 
machined  in  them  was  being  done  in  others  which  were  not  at  all 
adapted  for  it.  Thus  we  learn  that  in  order  to  get  the  maximum 
of  production  from  the  minimum  of  labor  we  must  always  con- 
sider and  select  the  machines  which  are  the  best  adapted  for  the 
work ;  as  well  as  pay  attention  to  the  designing  and  construction 
of  the  tools  and  fixtures  for  the  operations  necessary  to  finish  it. 
11 


CHAPTER  XII. 

Special  Tools,  Fixtures   and   Devices   for   Machining 
Repetition  Parts  in  the  Turret-Lateh. 

THE   USE  OF   SPECIAL   FIXTUEES  IN    THE    TUEEET- 

LATHE. 

If  there  is  one  type  of  machine  tool  that,  more  than  any 
other,  has  taxed  the  ingenuity  of  the  designer  and  the  skill  of 
the  tool -maker  to  keep  it  supplied  with  work,  it  is  the  turret- 
lathe  ;  as  the  numberless  varieties  and  classes  of  work  which  this 
great  factor  in  modern  manufacturing  is  capable  of  handling  are 
enormous.  When  I  state  the  above  I  do  not  refer  to  the  com- 
moner classes  of  work  produced  in  this  machine,  as  the  tools  for 
their  repetition  and  duplication  are  sufficiently  well  known  and 
understood  to  make  their  use  universal,  and  descriptions  of  them 
would  be  superfluous.  I  refer  to  the  special,  odd,  and  brain- 
racking  jobs  that  are  constantly  coming  along,  for  which  the 
ever-resourceful  tool-maker  is  required  to  construct  tools  so  that 
the  parts  may  be  turned  out  rapidly  and  accurately. 

For  the  production  of  parts  in  large  quantities  in  repetition, 
which  can  be  finished  by  turning,  boring,  or  facing,  no  other 
machine  tool,  when  equipped  with  suitable  tools,  offers  the  ad- 
vantages or  is  better  suited  than  the  turret-lathe,  or  its  elder 
brother,  the  screw-machine.  To  faciliate  the  production  and 
the  efficiency  of  the  machines,  and  reduce  the  responsibility  of 
their  operators  to  the  minimum,  thousands  of  tool -makers 
throughout  the  country  are  constantly  engaged  in  constructng 
devices,  fixtures,  tools,  and  arrangements.  It  is  with  these 
classes  of  tools  that  I  propose  to  deal  in  this  and  the  following 
chapter ;  devoting  this  one  to  the  use  of  special  tools  in  the  tur- 
ret-lathe and  the  next  to  the  use  of  similar  tools  in  the  screw- 
machine. 

162 


INTERCHA NGEABLE  MANVFA CTTJRING. 


163 


It  will  not  be  necessary  to  go  into  detail  in  regard  to  the 
standard  tools  used  in  connection  with,  the  various  devices  and 
arrangements  shown,  as  their  use  is  well  understood,  and  it 
would  be  digressing  unnecessarily  to  treat  them  or  the  machines 
in  detail.  In  regard  to  the  special  tools,  however,  too  much 
cannot  be  written. 

The  variety  of  the  tools  shown  and  the  description  of  their 
construction  and  use  will  warrant  a  careful  perusal  by  the  reader ; 
as  they  will  be  the  means  of  suggesting  modifications  of  the  de- 
signs which  can  be  embodied  in  tools  for  work  other  than  that 
shown  in  connection  with  them.  Tools  of  these  types  are  great 
reducers  of  cost  of  production ;  and  the  ability  to  devise  and 
install  them  successfully  is  an  enviable  capability  of  the  modern 
tool -maker. 


ATTACHMENT  FOE   FOEMING   IEEEGULAE   PIECES 
FEOM  THE  BAE. 

The  turret-lathe  fixture  shown  in  the  accompanying  engrav- 
ings is  for  forming  pieces  of  irregular  outline  from  the  bar.     It 


Fig.  164. 


Fig.  165, 


is  adapted  for  work  having  considerable  stock  to  be  removed, 
and  will  duplicate  the  pieces  very  accurately  and  leave  the  fin- 
ished surface  smooth  and  free  from  tool  marks.     As  it  is  always 


164 


TOOL-MAKING  AND 


ready  for  use  and  can  be  fastened  in  place  on  the  turret -lathe 
and  set  for  the  results  desired  in  short  order,  it  should  find  a 
place  in  all  shops  where  the  value  of  the  turret-lathe  is  appre- 
ciated. 

Figs.  164-165  are  front  and  back  views  of  the  fixture  com- 
plete, while  Fig.  166  is  a  side  view,  as  the  fixture  appears  when 
bolted  to  the  back  of  a  turret-lathe  cross-slide.  The  latter  view 
also  shows  the  manner  in  which  the  cutting-tool  is  presented  to 
the  work. 

The  fixture  proper  consists  of  two  main  parts  of  cast-iron,  the 
round  base  J  and  the  body  casting  I,  constructed  to  swivel  on  it. 


FIG.  166. 


The  front  G  of  the  body  casting  is  dovetailed  and  has  a  rib  _H"for 
the  steel  slide  G.  The  ribs  _ZV  N  act  as  strengthening  ribs  for  the 
front  and  also  as  bearings  for  the  pinion  and  lever-stud  0.  The 
steel  slide  G  and  an  oblong  opening  K  allow  the  rack  to  project 
through  the  front  G  and  mesh  with  pinion  Q.  This  allows  slide 
G  to  be  moved  up  or  down  by  the  lever  at  the  side.     The  pinion, 


INTERCHANGEABLE  MANUFA GTURING. 


165 


stud  Q  is  of  tool  steel  and  lias  a  large  head  at  one  end  and  is  re- 
duced arid  threaded  on  the  other  for  the  lever  and  fastening-nut 
P.     The  lever  and  pinion  are  keyed  to  the  stud. 

The  front  or  face  of  the  steel  slide  G  is  finished  on  an  incline 
at  approximately  the  angle  that  would  be  adopted  for  the  front 
clearance  of  a  lathe -tool.  This  is  done  so  as  to  avoid  having 
to  give  this  clearance  to  the  cutting-tool,  which  is  fastened  to 
the  face  of  the  slide,  and  requires  clearance  on  the  bottom  only. 


Fig.  167. 


The  cutting-tool,  as  shown  in  the  side  and  front  views,  is  located 
within  a  smaller  channel  in  the  face  of  the  steel  slide  C,  at  D,  and 
is  held  by  means  of  the  large  cap-screw  F.  The  cutting-edge  of 
the  tool  is  sheared  off  at  the  angle  shown  iu  the  front  view,  from 
A  to  B,  so  that  it  will  remove  the  metal  from  the  work  progres- 
sively. 

The  circular  portions  of  the  two  main  castings,  Fig.  164,  are 
so  constructed  that  the  body  of  the  tool  cau  be  swiveled,  there 
being  graduations  at  U  U  to  enable  it  to  be  set  accurately  at  the 
desired  angle  with  the  work.  The  base  J  is  provided  with  a 
tongue  L  which  fits  nicely  in  the  slot  for  the  tool-post  in  the 
turret-lathe  cross- slide.  The  main  casting  I  is  hollow  in  the 
center  to  allow  a  centre  hub  of  the  base  to  project  up  through 
it.     The  bolt  K,  by  which  the  base  is  secured  to  the  cross-slide, 


166 


TOOT^-MAKING  AND 


passes  up  through  this  hub  aud  thus  it  is  not  necessary  to  loosen 
the  base  when  swiveling  the  body  casting  or  tool-head.  To  Set 
the  tool-head  the  two  nuts  T  T  at  the  base  studs  are  loosened, 
and  the  head  graduations  set  to  the  angle  desired.  The  nuts  are 
then  fastened,  and  the  head  is  rigidly  held  in  position.  The 
manner  in  which  the  two  castings  are  finished  so  as  to  locate  true 
with  each  other  and  swivel,  is  shown  at  V  V  in  Fig.  1 66. 

As  a  practical  illustration  of  the  manner  in  which  the  fixture 
is  used,  there  is  shown  in  Fig.  167  a  plan  view  of  it  as  located 
and  fastened  to  the  lathe  cross-slide,  with  the  cutting-tool  in 
position  for  finishing  from  bar  stock  the  taper  end  of  a  mild 
steel  tool-post.  For  this  work  a  tail-stock,  equipped  with  cen- 
tre, replaces  the  turret  usually  employed  and  supports  the  end 
of  the  piece  being  formed  and  also  sets  the  gauge  for  length. 

In  machining  the  part  shown  in  Fig.  16S,  the  stock  is  fed  out 
the  required  distance,  and  the  spring-chuck  jammed.  The  tail- 
centre,  which  is  very  hard,  enters  the  bar  far  enough  to  support 


it.  The  handle  of  the  fixture  is  then  grasped  by  the  operator 
and  pulled  downward  until  the  lowest  point  of  the  cutting-tool 
at  A  is  somewhat  near  the  centre  of  the  revolving  stock.  The 
cross-slide  of  the  lathe  is  then  fed  forward,  and  the  tool  com- 
mences to  cut  until  the  slide  stops  against  the  stop -screw  and  the 
edge  of  the  tool  has  removed  considerable  stock.  The  slide  is 
now  held  securely  against  the  stop-screw  by  the  operator  x^ress- 
ing  down  hard  on  the  cross-slide  lever;  then  with  his  right  hand 
he  pulls  dowu  on  the  tool -head  lever,  thereby  feeding  the  cut- 
ting-tool downward,  and  the  stock  is  gradually  removed  by  the 
shearing  cut  of  the  tool,  and  the  bar  is  finished,  as  shown.  As 
each  portion  of  the  tool's  cutting-edge  removes  the  metal,  it 
passes  below  the  centre  of  the  bar  and  ceases  to  cut,  so  there  is 


INTERCHANGEABLE  MANUFA  CT TJBING. 


167 


only  a  narrow  surface  of  cutting-edge  of  the  tool  removing  metal 
at  the  one  time.  The  machining  of  the  work  is  thereby  pro- 
gressive ;  there  is  no  tendency  to  chatter  or  mark  the  work ;  and 
by  having  a  good  stream  of  oil  constantly  running  on  the  work, 
a  fine,  smoothly  finished  surface  is  the  result.  As  soon  as  the 
entire  cutting-edge  of  the  tool  has  passed  below  the  cenrte  of  the 
bar,  the  lathe  cross-slide  is  fed  back  to  its  former  position,  and 
the  cutting-tool  raised  for  the  next  piece.  In  order  to  produce 
the  best  results,  the  cutting-edges  of  the  tool  should  be  left  quite 
hard,  and  be  oil-stoned  to  a  perfectly  straight  and  keen  edge. 
The  amount  of  clearance  and  shear  has  also  considerable  effect 
on  the  results,  and  must  be  determined  by  the  quality  and  nature 
of  the  material  which  it  is  desired  to  machine. 

In  Fig.  169  is  an  illustration  of  a  piece  of  work,  the  taper 
surface  G  of  which  is  finished  by  the  use  of  the  special  fixture. 

/G 


Fig.  169. 


Fig.  170. 


In  Fig.  170  is  shown  a  special  turret-tool  used  for  supporting  the 
smaller  tapered  end  H  while  the  other  part  is  being  finished. 
The  stock  machined  was  a  f -inch  drill-rod,  and  the  long  taper  sur- 
face was  required  to  be  finished  as  smooth  and  clean  as  possible, 
and  slight  changes  were  made  in  the  tool  slide  to  accomplish 
these  desired  results.  The  slide  G  of  the  fixture  was  replaced 
with  another  that  differed  from  the  first  only  in  that  the  face 
was  left  straight  and  at  a  right  angle  with  the  cross-slide,  instead 
of  being  inclined  for  back  clearance.  Thus,  when  the  edge  of 
the  cutting-tool  passed  by  the  centre  of  the  stock,  the  portion 
machined  would  rub  against  it,  and  with  the  stock  rapidly  rotat- 
ing, the  friction  was  sufficient  to  give  quite  a  polish  to  the  ma- 
chined surface. 


168 


TOOL-MAKING  AND 


In  Figs.  172  and  173  are  shown  two  samples  of  work,  the 
formed  surfaces  of  which  were  machined  by  the  use  of  the  fixt- 
ure here  shown,  and  in  Fig.  171  is  a  sketch  of  one  of  the  cutting- 
tools  used  for  them,  from  which  an  idea  of  their  construction 
may  be  gained. 

The  great  saving  in  producing  work  of  this  class  direct  from 
bar  stock,  in  preference  to  using  separate  castings,  has  made  the 


Fig.  171. 

turret-lathe  as  great  a  factor  in  the  production  of  machine  parts 
as  the  engine-Jarhe.  For  that  reason  any  method  or  device 
which  will  add  to  the  capacity  of  the  machine  and  increase  the 
sufficient  of  output  should  be  adopted,  and  the  fixture  herein 
described  is  one  which  will  do  this.     It  can  be  easily  adopted  for 


ij4' 


a. 


-y 


Fig.  173. 

work  other  than  of  the  class  shown,  such  as  chandelier  and  elec- 
trical fixture  work,  where  large  quantities  of  ornamental  knobs, 
joints,  and  various  other  parts  are  produced  from  large  brass 
rods  or  bars ;  and,  in  fact,  for  producing  shaped  pieces  from  the 
bar  of  steel,  brass,  fibre,  or  hard  rubber. 


INTERCHANGEABLE  MA  N UFA  CTUEING. 


169 


BOX-TOOL   FOR   THE   TURRET-HEAD. 


In  Fig.  175  is  shown  the  pinion  as  used  in  drill-press  spindle- 
heads,  and  in  Fig.  174  the  tools  used  for  the  first  operation. 
These  pinions  were  of  cold-rolled  mild  steel,  and  were  roughed 
out  and  countered  at  each  end  in  the  turret-lathe.  The  box-tool 
shown  in  Fig.  174  and  a  cutting-off  tool  were  all  that  were  neces- 
sary for  it.  The  box-tool  is  finished  from  a  mild-steel  forging, 
which  is  first  centred,  and  the  stem  E  turned  to  fit  the  hole  in 
the  turret,  and  both  ends  faced.     It  was  then  located  on  the 


C 

1 
1 
1 

1 

ill 

B 

j 

ill 

Fig.  174. 


C 
Fig.  175. 


head  centre  and  set  to  run  true  in  the  steady  rest,  and  the  hole 
bored  in  the  face  for  the  bushing  G,  which  was  of  tool  steel, 
hardened  and  lapped  to  size,  to  fit  the  stock  to  be  worked.  The 
set-screw  L  holds  it  in  position.  A  hole  is  then  bored  and 
reamed  through  the  stem  E  for  the  centre-drill  K,  which  is 
fastened  within  it  by  the  headless  screw  M.  Two  cutting-tools, 
I  and  J  respectively,  are  let  into  the  box  as  in  the  position 
shown:  one,  I,  for  roughing,  set  slightly  in  advance  of  the 
other  one,  J,  which  finishes.  These  two  tools  are  hardened,  and 
drawn  to  a  light-straw  temper ;  a  set-screw  for  each,  on  the  side, 
holds  them  in  position.  When  using  the  tool,  the  bar  of  stock 
is  held  in  the  spring-chuck,  and  the  tools  J  and  J",  in  the  box- 
holder,  set  so  as  to  rough  down  the  stem  B  of  the  pinion-blank, 
Fig.  175,  as  shown,  leaving  enough  stock  to  allow  of  a  finishing 


170 


TOOL-MAKING  ANT) 


cut  being  taken  in  the  lathe,  and  then  grinding  them  to  size  in 
a  Lanis  grinder.  The  centre-drill  K  is  set  so  as  to  centre  the 
end  of  the  stem  at  the  same  time.  The  use  of  the  two  cutters  in 
the  box-tool,  as  shown,  acts  very  well,  and  reduces  the  time  on 
the  work  considerably,  removing  the  stock — as  it  does — all  in 
one  cut.  The  fastening  of  the  centre-drill,  K,  as  shown,  also 
contributes  to  reducing  the  time,  as  well  as  centring  the  stem 
true. 

TWO   SPECIAL   CHUCKS   FOE   THE  TUEEET-LATHE. 

In  Fig.  176  are  shown  two  views  of  a  special  chuck  used  for 
boring  and  facing  the  hubs  of  cast  bevel-gears.  This  chuck,  to- 
gether with  the  one  shown  in  Fig.  178,  is  used  for  the  machin- 


FIG.  176. 


ing  of  gears  which  are  used  in  large  quantities  on  cheap  ma- 
chines, and  their  use  allows  of  the  work  being  produced  in  a 
very  rapid  manner,  and  to  the  degree  of  accuracy  required  and 
as  cheaply  as  possible.  The  cross-sectional  view  of  this  chuck 
with  the  work  in  position  shows  clearly  the  design  and  method 
of  construction.  The  body  K  of  the  chuck  is  of  cast-iron,  and 
is  bored  out  and  threaded  at  the  back  to  fit  the  spindle  of  the 
turret-lathe.  It  is  then  finished  on  the  face  and  a  clearance-hole 
bored  at  L,  and  the  locating-seat  M  M  for  the  gear-face  fin- 


INTER GHA  NGEA  BLE  MANVFA  GT XJR1NG. 


171 


ished,  as  shown,  by  using  the  compound  rest,  and  setting  it  over 
as  required.  The  inside  of  the  chuck  is  then  threaded  for  the 
fastening-lid  at  P  P.     This  lid  is  also  of  cast-iron,  finished  as 


Fig.  177. 


shown,  with  two  handles  at  Q  Q  and  a  clearance-hole  R  in  the 
centre  for  the  hub  of  the  work.  Six  pins,  two  of  which  are 
shown  at  X  X,  serve  to  drive  the  work,  by  engaging  the  teeth  of 


Fir,.  17 


the  gear  as  shown.  When  in  use  the  chuck  is  screwed  on  to  the 
spindle  of  the  turret-lathe  and  the  lid  removed.  The  gear,  as 
shown  at  N,  is  then  placed  within  the  chuck,  with  the  driving- 


172  TOOL-MAKING  AND 

pins  within  the  teeth.  The  lid  is  then  screwed  on  and  forces  the 
bevel- face  of  the  gear  against  the  locating-surface  M  M  of  the 
chiK'k,  truing  it  and  holding  it  securely.  The  hole  is  then  bored 
at  0,  and  the  hub  faced  by  the  use  of  the  combination  tool 
shown  in  Fig.  177.  By  the  use  of  this  chuck,  the  hole  in  the 
gear  is  bored  and  finished  true  with  the  gear-face,  which  iu  cast- 
iron  gears  is  absolutely  necessary,  in  order  for  the  gears  to  run 
well  when  assembled. 

The  chuck  shown  in  Fig.  178  is  of  a  much  simpler  design 
and  construction;  but  is  just  as  useful  and  rapid  in  production 
for  the  class  of  work  for  which  it  is  used  as  the  other.  It 
consists  of  one  body  casting  A  which  is  bored  and  threaded  at 
back  to  fit  the  turret-lathe  spindle,  and  bored  on  the  face  of  the 
clearance-hole  at  G  and  at  B  B  as  a  truing  point  for  the  gear- 
face  of  the  work  F.  The  work  is  fastened  in  position  by  the  two 
clamps  1 1.  The  spring  E  around  each  of  the  clamp-studs  con- 
tributes to  the  rapid  locating  of  the  work  and  its  removal  when 
finished.  The  work  is  driven  by  the  stud  steel  pin  L  as  shown, 
and  can  be  located,  fastened,  and  machined  in  a  very  rapid  man- 
ner, as  a  turn  of  the  thumb-nuts  J  J"  releases  the  clamps,  which 
are  raised  above  the  work  by  the  springs  E  E,  and  the  work  0 
can  be  slipped  out  and  another  gear  located  and  fastened  in  its 
place  in  very  short  order.  The  hole  is  bored  in  these  gears,  and 
the  hub  faced  by  means  of  a  tool  similar  to  the  one  shown  in  Fig. 
177.  After  boring  the  hole,  it  is  finished  to  size  by  the  usual 
chucking-reamer  and  finishing  "floating"  reamer,  which  insures 
the  hole  being  round  and  true. 


DETAIL   SKETCHES   OF   TOOLS   AND    FIXTUEES    FOR 
MACHINING   PULLEYS. 

The  set  of  tools  of  which  sketches  are  here  shown  were  de- 
signed by  the  author  for  finishing  countershaft  clutch-pulleys  in 
the  turret-lathe,  and  have  been  very  successfully  used  for  this 
purpose.  It  was  desired  to  turn  out  the  pulleys  in  large  quan- 
tities, and  to  have  the  work  accurately  done,  making  them  dupli- 
cates so  far  as  their  finished  dimensions  were  concerned.     The 


INTERCHANGEABLE  MANTJFACTVRING. 


173 


tools  were  so  constructed  that  the  pulleys  could,  be  finished  com- 
plete at  one  setting. 

The  type  of  pulleys  which  this  particular  set  of  tools  was  de- 
signed to  machine  is  shown  in  the  two  views  in  Fig.  179,  and 
consists  of  a  six-arm  pulley  of  a  common  type.  The  points  to 
be  machined  are  as  follows:  The  hole  was  to  be  bored  and 
reamed  and  one  end  of  the  hub  faced ;  the  sides  of  the  rim  were 
to  be  faced,  and  an  interior  portion  of  the  rim  bored  and  finished 


Fir.  17 


on  a  very  slight  taper,  as  shown,  for  the  friction  or  rubbing  sur- 
face of  the  chuck  ;  and,  finally,  the  face  of  the  pulley  had  to  be 
crowned  and  finished. 

In  order  to  accomplish  all  these  operations  at  one  handling 
of  the  piece,  all  the  tools  had  to  be  specially  constructed  for  the 
purpose.  They  consisted  of  a  chuck  for  holding  the  work 
while  being  machined,  a  combination  and  boring  hub-facing 
tool,  a  turret  fixture  for  boring  and  finishing  the  clutch  portion, 
and  a  special  compound  slide-rest,  with  cutting-tools  at  the  back 
and  front. 


174: 


TOOL-MAKING  AND 


Two  views  of  the  chuck  are  shown  in  Figs.  180  and  184,  and 
the  several  parts  of  the  chuck  appear  in  detail  in  the  other  fig- 
ures.    The  chuck  so  holds  the  work  that  all  points  to  be  ma- 


FIG.  180. 


chined  are  easily  accessible  to  the  cutting-tools.     There  are  nine- 
teen parts  in  the  chuck.     The  body  is  a  forging  of  mild  steel, 

i  l  I 


Fig.  181.' 


and  is  bored  and  threaded  at  the  back  to  fit  the  spindle  of  the 
turret-lathe.  There  are  three  projecting  lugs  or  false  jaws  II I, 
as  shown,  and  the  faces  of  these  were  turned  off  to  form  three 


INTERCHANGEABLE  MANUFACTURING.        175 

even  supports  for  three  of  the  pulley  arms.     The  outside  sur- 
faces K  K  of  the  lugs  were  turned  to  a  suitable  diameter  for  the 

o 


FIG.  182. 


FIG.  183. 


Fig.  184. 


purpose  of  locating  the  pulley  in  a  central  position  by  means  of 
the  inside  of  the  pulley  rim,  which  comes  in  contact  with  these 


Fig.  185. 


SCREW  PLATE 


Fig.  186. 


JAW  OF  CHUCK 


ll 

I!1 

. ' 

V 

r  i 
V- 

1 

,1 

III 

i 

1  '• 

1     i 

n 

w 

iw 

i..  I.    r 

i1 
ii  |'i 

1 
1 

!l  li 
ll 

Fig.  187. 


Fig.  188. 


surfaces  K  K  when  the  pulley  is  held  in  the  chuck.     The  sur- 
faces K  and  I  of  each  lug,  therefore,  determine  the  position  of 


176 


TOOL-MAKING  AND 


the  pulley  with  sufficient  accuracy  for  machining  while  the  arms 
are  clamped  securely  by  the  jaws  0  0  0. 

The  construction  and  operation  of  the  chuck  will  be  clearly 
understood  from  the  engravings,  and  it  will  be  seen  that  the  pul- 
ieys  can  be  clamped  in  position  or  removed  very  readily.  The 
three  jaws  OOO  which  grip  the  spokes  of  the  pulley  and  draw 
them  against  the  faces  of  the  false  jaws,  are  moved  in  or  out,  as 
required,  by  simply  tightening  or  loosening  the  wedge-screw  P, 
which  raises  or  lowers  the  wedges  N,  as  shown  in  the  sectional 
view  of  Fig.  184.  In  making  the  chuck  it  is  interesting  to  note 
that  the  finishing  of  the  rectangular  holes  L  and  31,  Fig.  181,  in 


Fig.  189. 

which  slide  the  wedges  iVand  jaws  0,  was  accomplished  by  the 
use  of  broaches  of  the  type  shown  in  Fig.  188.  For  such  work 
the  broach  should  be  constructed  with  very  coarse  teeth  on  the 
lower  end  to  take  out  the  bulk  of  the  stock.  It  will  be  noticed 
that  the  teeth  on  the  two  ends  of  the  broach  are  so  inclined  as  to 
give  shearing  cuts  in  opposite  directions,  the  object  of  this  being 
to  break  off  the  chips  as  the  broach  passes  through  the  work. 
The  upper  end  of  the  broach  is  left  perfectly  straight  for  about 
two  inches  and  serves  as  a  "sizer."  The  broaching  of  the  holes 
is  accomplished  by  forcing  the  broach  completely  through  them 
under  the  power-press.  The  machining  of  the  other  parts  of  the 
chuck  presents  no  difficulties  and  will  be  understood  by  reference 
to  the  figures.  All  parts  except  the  body  of  the  chuck  are  of 
tool  steel,  and  all  wearing  surfaces  were  hardened  and  tempered. 
The  combination  boring  and  hub-facing  tool-holder  is  shown 
in  Fig.  189.  After  the  hole  in  the  pulley  is  bored  and  the  hub 
faced  by  this  tool,  it  is  finished  by  the  small  chucking  reamer 
and  by  a  finishing  reamer  of  the  "  floating  "  type,  to  insure  the 
hole  being  true  and  round. 


INTERCHANGEABLE  MANTJFA CTUEING. 


177 


The  special  turret-tool  for  finishing  the  clutch  portion  of  the 
pulley  is  shown  in  Fig.  190,  and  details  of  the  parts  in  Figs.  191, 
192,  and  193.  The  three  cutting-tools  are  held  in  dovetailed 
channels  finished  to  an  angle  of  three  degrees  with  the  centre 
line  of  the  fixture,  this  being  the  angle  of  the  chuck  surface  on 
the  interior  of  the  pulley  rim.     Having  the  grooves  finished  at 


Fig.  190. 

this  angle  makes  it  easier  to  set  the  cutters  correctly,  and  as  the 
cutters  are  held  by  clamping  they  can  be  adjusted  to  remove  the 
right  amount  of  metal. 

In  Fig.  194  is  a  plan  view  of  the  special  compound  slide-rest, 
with  the  cutting-tools  in  position.  This  slide-rest  consists  of  the 
main  casting  A,  which  is  fitted  to  the  carriage  of  the  turret-lathe, 
replacing  the  cross-slide;  of  the  compound  rest  B  and  O,  in 
which  the  gashing-  or  roughing-tools  are  held ;  and  of  the  face 
crowning-  and  finishing-tool  fastened  within  the  main  casting  A 


Fig.  191. 


in  a  dovetailed  groove  at  the  back,  as  clearly  indicated  in  Fig. 
195.  There  are  seven  roughing-tools  and  two  side  tools,  located 
in  channels  in  the  slide  G  and  fastened  by  the  set-screw  in  the 
strap  D — the  six  short  ones  for  gashing  the  scale  and  roughing 
off  the  face,  and  the  other  two  for  facing  the  sides  of  the  pulley 
rim.     The  face  crowning-  and  finishing-tool  is  located  in  such  a 


178 


TOOL-MAKING  AND 


position  in  the  body  plate  A  that  its  cutting -edge  will  operate  in 
a  line  tangent  to  the  periphery  of  the  pulley ;  and  as  the  tool  is 
designed  to  make  a  shearing  cut,  the  metal  is  removed  progres- 
sively from  one  side  of  the  pulley  to  the  other,  thus  reducing  the 


Fig.  192. 


Fig.  193. 


strain  and  the  tendency  to  chatter.  A  plan  of  the  slide-rest  is 
given  in  Fig.  194,  and  in  Fig.  195  is  the  elevation,  which  also 
shows  the  manner  of  holding  the  pulley  in  the  chuck. 

Eeferring  to  Fig.  195,  it  will  be  seen  that  the  pulley  is  se- 
cured in  the  chuck  by  slipping  the  spokes  into  the  notches  of  the 


Fig.  194. 


jaws  and  tightening  the  wedge-screws  P  so  as  to  draw  the  spokes 
tightly  against  the  locating-faces,  as  shown.  The  hole  in  the 
pulley  is  then  bored  and  the  hub  faced  by  the  combination  tool 
shown  in  Fig.  189,  after  which  the  clutch  portion  is  finished  by 
the  fixture  shown  in  Fig.  190,  the  leading  stud  supporting  the 
work  while  it  is  being  machined,  and  remaining  in  the  hole  until 
the  pulley  has  been  finished.     The  face  gashing-  or  roughing- 


moving  all  that  is  necessary  to  clean  them  up. 


INTERCHANGEABLE  MANUFA  CTUBING. 


179 


To  crown  and  finish  the  pulley,  the  whole  slide-rest  is  fed 
out  by  the  cross-feed  screw  of  the  carriage  until  the  entire  cut- 
ting-edge of  the  crowning-  and  finishing-tool  has  passed  beneath 


Fig.  195. 

it  and  finished  and  sized  it  to  the  shape  and  size  required.  The 
use  of  this  set  of  tools  insures  an  exact  duplication  of  the  work 
produced  at  a  low  cost. 

There  is  one  thing  that  must  not  be  lost  sight  of,  when  con- 
structing a  forming-  and  finishing-tool  of  the  type  shown  here, 


Fig.  196. 

for  crowning  the  pulley :  As  the  face  or  cutting-edge  is  finished 
and  ground  so  as  to  take  a  shearing  cut,  and  the  tool  is  located  in 
such  a  position  in  the  main  casting  as  to  give  it  the  required 
clearance-angle,  the  forming-face  must  be  finished  as  shown  at 
B,  Fig.  196.  As  the  tool  is  set  at  an  angle  with  the  face  of  the 
pulley,  in  order  to  produce  the  shape  desired,  one  side  must  be 
considerably  higher  than  the  other,  as  at  B.  This  should  be 
figured  out  and  a  templet  made,  according  to  the  degree  of  clear- 
ance given  and  the  amount  of  shear  to  the  cutting-face. 


180 


TOOL-MAKING  AND 


TOOLS  FOR   MACHINING  A  SPECIAL   CASTING. 

The  hood-shaped  casting  shown  in  Fig.  197  formed  part  of 
an  electrical  appliance  which  was  being  manufactured  in  large 
numbers  and,  as  it  is  a  characteristic  piece  of  duplicate  work, 


FIG.  197. 

the  method  employed  in  its  production  may  prove  of  interest  to 
my  readers. 

The  operations  necessary  for  machining  this  casting  were, 
first,  to  drill  and  ream  the  ^--inch  hole  A;  second,  face  the  base 
B ;  third,  finish  the  circular  portion  C  C  given  diameter  and 


Fig.  198. 


taper ;  and,  finally,  to  drill  the  ^-inch  holes  through  the  centre  of 
each  of  the  four  parts  D.  The  first  and  second  operations  were 
both  performed  in  a  turret-lathe  with  the  casting  held  in  a  four- 
jaw  chuck,  as  shown  in  Fig.  198.     The  hole  A  was  first  bored 


INTERCHANGEABLE  2IANUFA  CTTJRING. 


181 


with  the  usual  turret  boring-tool  and  reamed  to  size  with  a 
''floating  "  reamer.  The  work  was  then  driven  slowly,  by  throw- 
ing in  the  back  gears ;  and  the  second  operation,  that  of  facing 
the  base  B  was  performed  by  the  use  of  a  large  face  milling-cut- 
ter, placed  on  an  arbor  which  was  held  in  the  turret-head,  as 
shown  in  Fig.  198.  This  cutter  was  of  the  ordinary  type  of 
facing -cutter,  except  that  the  teeth,  on  the  facing  side,  were 
staggered  to  prevent  chatter.  The  cutter,  which  was  driven  by 
the  key  K  was  held  in  place  on  the  arbor  by  the  nnt  N  and 
washer  W. 

With  this  cutter  it  was  possible  to  machine  a  large  number  of 
castings  before  it  required  to  be  ground. 

The  third  operation,  that  of  finishing  the  circular  taper  sur- 
faces G  G,  was  accomplished  as  shown  in  Fig.  199  by  the  use  of 


Fro.  199. 


an  end-mill  in  a  universal  milling-machine.  The  work  was  held 
on  an  arbor  between  the  tail  and  dividing-head  centres  and  the 
swivel  carriage  moved  around  until  the  table  and  arbor  stood  at 
the  desired  angle  with  the  face  of  the  milling-cutter.  After  set- 
ting the  work  so  that  the  desired  amount  of  stock  would  be  re- 
moved, the  cross- feed  screw  was  clamped,  and  the  work  fed 
against  the  cutter  by  revolving  the  dividing-head  by  hand.  For 
the  last  operation,  that  of  drilling  the  holes  D  D,  the  jig  shown 
in  Fig.  200  was  constructed.     This  jig  was  made  in  two  parts,  a 


182 


TOOL-MAKING  AND 


body  casting  in  which  the  work  was  located,  and  a  lid  W,  which 
was  hinged  at  one  side  and  carried  the  four  tool-steel  bushings 
B  B  by  means  of  which  the  holes  were  located  and  drilled. 

A  hinged  bolt  and  thumb -nut  Q  served  to  clamp  the  two 
parts  together  when  the  jig  was  in  use. 

The  bottom  of  the  body  was  bored  out  to  correspond  in  taper 
and  diameter  with  the  taper  surfaces  of  the  work  at  C  C.  Ex- 
tending inward  from  one  side  of  this  hole  was  a  lug  K  in  which 
was  fitted  the  stop -pin  Z.     The  stem  of  this  pin,  where  it  fitted 


FIG,  200. 


the  stop-lug,  was  eccentric  with  the  body  of  the  pin,  so  as  to  pro- 
vide for  adjustment,  while  the  screw  J  locked  the  pin  in  p]ace 
when  the  proper  adjustment  was  attained. 

This  pin  was  brought  against  one  of  the  inner  lugs  of  the 
castings,  as  at  E,  and  thus  located  the  lugs  in  the  proper  position 
to  be  drilled. 

When  in  use  the  swinging  clamp  Q  is  released  and  the  lid  W 
thrown  back.  The  work  is  then  slipped  into  the  body  and  lo- 
cated within  the  taper  seat  and  against  the  stop -pin  Z.  The 
lid  is  then  brought  down  by  grasping  the  handle  8  and  as  the 
spring  pad  TJ  strikes  the  work,  the  tension  of  the  spring  0  0 
enables  it  to  force  it  tightly  down  on  the  locatlng-seat.  The  lid 
is  then  held  down  on  the  body  casting  with  one  hand,  while  the 
swinging  clamp  is  swung  up  and  fastened  with  the  other.  The 
casting  is  then  drilled  through  the  bashings  B  B.  One  of  the 
best  features  of  the  jig  is  the  impossibility  of  the  chips  and  dirt 
interfering  with  the  accurate  and  positive  locating  of  the  work. 


INTERCHANGEABLE  MANTJFA  CTUBING. 


183 


A  MULTI-SPINDLE  DRILLING  AND   TAPPING   AT- 
TACHMENT  AND   WORK   FIXTURE. 

The  special  multi-spindle  drilling  and  tapping  attachment 
and  its  work  fixture,  shown  in  the  accompanying  illustrations, 
were  designed  by  the  writer.  The  work  shown  in  Fig.  201  is  a 
circular  casting  with  a  large  central  hole  and  six  small  holes  a  a. 
It  was  for  drilling  and  tapping  these  six  holes  that  the  attach - 


FIG.  201. 

ment  here  shown  was  designed,  and  as  it  proved  a  great  cost-re- 
ducer and  allowed  the  required  degree  of  interchangeability  at 
the  minimum  of  cost,  its  adaptability  for  a  large  variety  of  work 
is  apparent.  It  also  shows  another  use  to  which  the  ever  handy 
— and  often  idle — turret-lathe  may  be  put. 

The  six  holes  for  the  casting  are  equally  divided  around  a 
circle  concentric  with  the  large  hole  c  c,  and  are  drilled  entirely 
through  the  bosses.  The  large  hole  is  bored  and  one  side  of  the 
bosses  faced  in  a  preceding  operation  in  the  turret-lathe,  and 
the  keyway  is  let  in  so  as  to  be  in  the  same  relative  position  to 
the  bosses  in  all  of  the  castings. 

Fig.  202  shows,  partly  in  section,  the  fixture  complete  and 
also  several  of  the  main  parts.     Fig.  203  is  a  plan,   with  the 


184 


TOOL-MAKING  AND 


arrangement  of  the  gears  and  their  relative  positions  on  the  sta- 
tionary spindle-disk.  As  shown  in  Fig.  202,  the  attachment 
consists  of  three  main  parts,  of  which  A  is  the  driver,  C  the  sta- 
tionary spindle  and  leading  stud.  The  driver  A,  of  cast-iron, 
was  finished  first,  boring  it  out  at  the  back  and  then  threading 
it  to  fit  snugly  the  spindle  of  the  turret-lathe.  A  hole  was  then 
bored  straight  through  from   the  face    at  B  and   threaded  as 


FIG.  202. 


shown,   getting  it  dead  true.     The  front  was  then  faced,  thus 
insuring  the  lubrication  of  the  entire  surface. 

The  stationary  disk  C,  a  circular  casting  with  bosses  on  each 
side,  to  the  number  of  thirteen  on  the  front  and  seven  on  the 
back,  was  then  machined.  The  central  hole  for  the  spindle  D 
was  first  bored  and  reamed  to  size,  a  mandrel  was  driven  in,  and 
both  sides  were  faced,  leaving  all  the  bosses  the  same  height. 
We  were  now  ready  to  locate  and  finish  the  holes  for  the  six 
spindle-gears  H  and  the  intermediate  gears  K.  A  stud  of  tool 
steel  was  turned  up,  hardened  and  ground  to  fit  the  central  hole 
in  the  disk  tightly.     We  then  finished  up  six  buttons  of  the  type 


INTERCHANGEABLE  MANUFACTURING. 


185 


used  for  accurate  jig-making,  aucl  ground  them  to  ■g-'-inch.  on  the 
outside  and  the  ends  perfectly  square.  The  central  stud  was 
entered  into  the  hole  and  one  of  the  buttons  was  located  the 
exact  distance  from  the  centre  by  using  the  verniers  and  deduct- 
ing the  diameter  of  the  stud  and  button.  The  button  was  then 
fastened  to  the  disk  by  its  screw,  being  located  as.  nearly  in  the 
centre  of  the  bosses  as  possible.  The  second  button  was  located 
the  required  distance  from  the  first  and  from  the  centre  of  the 
stud  in  the  same  manner,  and  this  operation  was  repeated  until 
all  sis  buttons  were  located. 

The  disk  was  clamped  on  the  lathe  face-plate  and  the  central 
stud  removed.     The  first  button  was  trued  and  removed,  and  a 


FIG.  203. 


£-inch  hole  drilled,  bored,  and  reamed  entirely  through  the  disk. 
The  next  button  was  then  located,  trued,  and  removed  and  the 
hole  bored  and  finished  in  the  same  manner ;  repeating  until  the 
six  holes  were  finished.  We  were  now  sure  of  the  accuracy  and 
position  of  the  gears  when  placed,  and  the  interchangeability  of 
the  holes  when  drilled.  Before  drilling  and  tapping  the  holes 
for  the  six  intermediate  gears,  the  gears  were  turned  and  cut. 

The  drill-chuck  spindles  and  gears  were  each  in  one  piece  and 
were  mild-steel  forgings  which  were  first  centred  and  faced  the 
same  length.  The  spindle  portions  G  were  turned  to  within 
.005-inch  of  the  finish  size  and  the  ends  threaded  for  the  nut, 


186 


TOOL-MAKING  AND 


leaving  a  shoulder  for  the  washer.  The  taper  portion  for  the 
chuck  was  turned,  leaving  the  same  amount  of  stock  for  finish- 
ing as  on  the  other  end.  The  gear  portion  J?  was  then  finished 
to  the  required  diameter,  and  all  were  finished  in  the  grinder, 
with  the  portion  G  a  smooth  running  fit  in  the  reamed  holes  in 
the  disk,  and  the  sides  of  the  gears  ground  perfectly  flat  and  true 
with  the  spindles.     The  teeth  were  then  cut. 

The  six  intermediate  gears  K  also  were  of  steel;  and  six 
shoulder-studs  or  screws  were  made  of  tool -steel  for  them.     The 


Fig.  204. 


large,  or  driving-gear  F  was  of  cast-iron  and  was  bored  and 
reamed  to  the  same  size  as  the  central  hole  in  the  disk ;  the  sides 
were  ground  as  the  others,  and  a  keyway  let  in  for  fastening  it 
to  the  spindle  and  leading  stud  D.  The  portion  D  of  the  stud 
turned  within  the  disk  after  hardening.  A  second  shoulder  was 
left  at  M  so  that  the  space  between  it  and  the  first  would  accom- 
modate the  disk  and  the  driving  gear.     A  hexagon  was  milled 


INTERCHANGEABLE  MANUFA CTURING. 


187 


at  M  and  the  stud  reduced  for  the  remainder  of  its  leugth,  the 
eud  rounded  to  act  as  a  leading  stud  and  enter  a  reamed  hole  in 
the  work  fixture  when  in  operation,  to  support  it.  The  six  holes 
for  the  intermediate-gear  screws  were  then  drilled  and  tapped, 
so  that  the  gears  would  occupy  the  positions  shown  in  the  plan. 
After  drilling  and  tapping  the  hole  for  the  stud  B  B  all  parts 
were  assembled,  as  shown,  the  chucks  being  driven  tightly  on  to 
the  spindles. 

The  fixture  for  locating  and  fastening  the  work  is  shown  in 
Fig.  204.  The  body  casting  is  machined  first.  After  being  cen- 
tred it  has  the  stem  turned  to  fit  the  hole  in  the  turret-head.    It  is 


Fig.  205. 

then  reversed  and  held  by  the  finished  stem  in  a  nose-chuck  and 
the  front  is  finished,  first  taking  a  cut  off  the  two  projecting 
bosses  G  G,  then  finishing  the  seat  for  the  work  and  turning  the 
hub  D  to  fit  nicely  the  large  central  hole  in  the  work  (under 
cutting  it  at  the  back  to  prevent  dirt  or  chips  from  accumulat- 
ing), and,  lastly,  boring  and  reaming  the  centre  hole  E  for  the 
leading  stud  of  the  drilling  and  tapping  attachment.  Before 
locating  and  letting  in  the  key  F  in  the  hub  D  the  lid  was  fin- 
ished and  fastened  to  the  body  casting  and  the  holes  for  the  drill - 
bushings  were  let  in. 

This  lid-casting  is  circular,  with  a  large  hole  L  in  the  cen- 
tre and  raised  bosses  at  the  opposite  sides  where  it  is  hinged  and 
located  to  the  body  casting.  These  bosses  were  faced  and  a  cut 
was  taken  off  one  side  of  the  casting  for  the  bushing-heads  to 


188  TOOL-MAKING   AND 

locate.  The  lid  and  the  body  casting  were  then  clamped  to- 
gether so  that  the  boss  faces  rested  true  with  each  other,  and  the 
hole  for  the  hinge-screw  H  was  let  in,  tapping  it  in  the  body 
casting  and  enlarging  and  reaming  it  to  a  snug  fit  for  the  large 
portion  of  the  screw  in  the  lid.  The  screw  H  was  then  let  in 
and  the  hole  I  drilled  aud  reamed  for  the  taper  locating-stud  J. 
We  were  now  ready  to  locate  and  finish  the  bashing-holes.  The 
taper  locating-pin  J  was  forced  in  tightly  and  a  hardened  and 
ground  plug  was  finished  to  fit  tightly  the  hole  E.  Then  by 
using  the  buttons  used  for  locating  the  spindle  holes  in  the 
drilling  and  tapping  attachment  these  six  holes  were  located  in 
the  same  manner.  The  hinge-screw  H  and  the  locating-stud  J 
were  then  removed,  the  lid  was  clamped  to  the  face-plate,  the 
buttons  made  true,  and  holes  bored  aud  reamed  to  the  required 
size.  The  bushings  K  were  made  of  tool  steel  and  forced  into  the 
holes  in  the  lid.  Three  holes  were  then  drilled  and  tapped  in 
the  body  casting  in  the  positions  shown  by  the  dotted  lines  in 
Fig.  204  to  accommodate  the  clamp -screws.  These  three  clamps 
are  only  used  when  tapping  the  holes,  the  lid  being  then 
removed.  After  the  six  clearance-holes  for  the  drills  and  taps 
Mere  drilled  and  the  key  let  in  so  that  the  bosses  of  the  casting- 
would  cam  approximately  correct,  the  fixture  was  complete. 

In  Fig.  205  is  shown  the  manner  of  setting  up  the  multi -spin- 
dle attachment  and  the  work  fixture.  The  driver,  or  back  plate 
of  the  attachment  is  screwed  on  to  the  spindle  of  the  turret-lathe. 
A  clamp -strap  of  finch  thick  flat  iron,  bent  to  the  shape 
required,  with  a  hole  in  the  centre  for  the  stud  B  B,  Fig.  213, 
and  the  ends  bent  inward  and  set-screws  let  in,  was  then  secured 
with  the  ends  fastened  to  the  body  of  the  lathe  and  the  stud 
B  B  fastened  to  the  strap  by  the  nut,  thereby  locating  and  fast- 
ening the  spindle-disk  without  the  possibility  of  shifting  when 
in  operation. 

The  work  fixture  was  located  by  entering  the  stem  into  one  of 
the  holes  in  the  turret-head,  the  slide  moved  up,  and  the  fixture 
manipulated  until  all  six  drills  entered  the  bushings  of  the  fixt- 
ure. The  fixture  was  then  fastened,  the  lid  was  thrown  back, 
the  work  or  casting  to  be  drilled  located  by  the  key  on  the  hub 
of  the  fixture,  as  shown,  and  the  lid  or  bushing-plate  relocated 


INTERCHANGEABLE  MANUFACTURING.         189 

by  the  taper  plug.  The  lathe  is  started,  and  as  the  driver 
revolves,  and  with  it  the  driving  gear,  the  spindle-disk  remains 
stationary,  allowing  the  six  drills  to  turn  at  the  speed  desired. 
The  turret-slide  is  moved  up,  the  six  holes  are  drilled  in  the 
work,  the  finished  piece  removed  and  replaced  by  another,  and 
the  operation  repeated.  After  all  the  castings  in  the  lot  have 
been  drilled  they  are  tapped  by  simply  substituting  taps  for  the 
six  drills  and  removing  the  bushing-plate  from  the  work  fixture. 
The  locating  of  the  castings  so  that  alignment  of  the  drilled  holes 
with  the  taps  will  be  perfect  is  accomplished  without  any  trouble, 
as  the  keyway  in  the  casting  brings  them  in  the  same  location 
as  in  the  first  or  drilling  operation,  and  the  three  clamps  hold  it 
tightly  in  position.  When  tapping,  the  spindles  are  run  at  the 
proper  speed  and  the  work  is  brought  up  to  the  taps,  the  opera- 
tor keeping  his  hand  on  the  shifter,  and  as  soon  as  the  taps  have 
come  through  the  holes  the  lathe  is  reversed  and  the  taps  are  fed 
out. 


CHAPTER  XIII. 

Special  Tools,  Fixtures,  and  Devices  for  Machining 
Repetition  Parts  in  the  Screw-Machine. 

FOUR  SPECIAL   BOX-TOOLS   FOR   THE   SCREW- 
MACHINE. 

The  tools  shown  and  described  in  this  chapter  were  designed 
for  and  used  in  the  screw-machines,  but  many  of  the  designs  are 
adaptable  with  slight  modifications  to  the  turret-lathe  as  well. 

The  tools  shown  in  Figs.  206  to  209  are  for  making  small  tubes 
used  for  perforating  leather  shoe-tips.  These  tubes  run  from 
tV  t°  i-inch  in  diameter,  are  made  from  drill  rod,  and  are  re- 


FIG.  206. 

quired  to  be  finished  with  a  smooth  reamed  hole  through  them 
true  with  the  outside,  and  with  one  end  chamfered  to  a  sharp 
edge.  In  producing  the  larger  sizes  of  tubes  very  little  trouble 
was  encountered,  but  for  the  smaller  sizes  (and  they  were  required 
in  the  largest  quantities)  much  trouble  was  met  with.  All  trou- 
ble, however,  was  overcome  and  very  good  results  attained  by 
the  use  of  the  tools  shown  herein. 

Fig.  206  is  for  chamfesing  the  ends  and  centring  the  tubes. 
The  body  or  box  portion,  of  cast-iron,  has  a  hole  through  it  for 

190 


INTERCHANGEABLE  MANUFA  GTUBING. 


191 


the  entering-tool  JPand  its  adjusting-screw  C.  A  hole  is  broached 
through  the  body  for  the  chamferiug-tool  C,  at  au  angle  which 
allows  the  face  of  C  to  be  ground  square.  The  bushing  G  is  of 
tool  steel,  is  hardened  and  lapped  to  the  size  of  the  drill-rod. 


Fig.  207. 

By  chamfering  the  end  of  the  tubes  with  this  tool,  before  drill- 
ing and  reaming  the  hole,  a  sharp  edge  can  be  produced. 

Fig.  207  shows  the  tool  for  drilling  the  tubes.  The  drill  is 
held  in  a  split  bushing  by  the  adjusting-screw  K  and  round- 
head screw  N.     The  bushing  L  is  forced  into  the  holder. 

Fig.  208  is  for  cutting  off  the  tubes.  On  account  of  their 
smaller  diameter  it  is  necessary  to  support  the  stock  during  the 
operation.  The  body  of  the  tool  is  of  cast-iron.  The  cuttlng- 
off  tool  is  of  a  somewhat  special  construction.  It  is  of  a  ^  x  ■£-- 
inch  stock  finished  all  over  to  fit  within  the  channel,  and  with  a 


Fig. 


groove  in  one  side  for  the  feather  U.  The  grooves  Ton  the  bot- 
tom are  for  the  collar  of  the  feed-screw  W.  The  cutting  end  of 
the  tool  T  is  finished  to  the  usual  shape  required  for  such  a  tool ; 
as  narrow  as  possible,  accordiug  to  the  size  of  the  stock.  These 
three  tools  produce  the  perforating  tubes  to  the  degree  of  inter- 
changeability  and  accuracy  required,  and  in  a  very  rapid  man- 


192 


TOOL-MAKING  AND 


ner.  The  tubes,  after  being  thus  finished,  are  hardened  and 
tempered  to  a  dark  blue,  and  are  forced  into  radial  holes  in  a 
mild-steel  disk.  Different  combinations  of  sizes  of  tubes  are 
located  in  these  disks,  to  produce  the  pattern  desired  in  their 
leather  shoe-tips  and  miscellaneous  leather  findings. 

The  box-tool,  Fig.  209,  is  of  a  distinctly  different  type  from 
those  above  described ;  it  is  used  for  pointing  slender  needle  valves 
on  an  incandescent  oil-lamp  of  well-known  make.  It  is  rather  dif- 
ficult to  point  wire  of  small  diameter  by  the  ordinary  means  avail- 
able in  the  screw -machine,  especially  if  the  points  are  to  taper 


Fig.  209. 

quite  gradually,  as  at  M.  By  the  ordinary  method  the  cutting 
surface  of  the  tool  would  be  so  wide  that  it  would  be  almost 
impossible  to  keep  the  wire  true  and  hold  it  sufficiently  rigid. 
The  body  or  box  portion  of  the  tool  is  a  forging  of  mild  steel, 
with  a  rectangular  hole  at  B  and  a  tool -steel  bushing  at  C.  The 
cutting-tool  E  is  fitted  snugly  into  a  square  broached  hole,  the 
side  of  which  is  in  line  with  the  end  of  the  bushing.  The  rear 
end  of  the  tool  is  threaded  for  adjustment  nut  O.  A  bracket  is 
fastened  to  the  body  of  the  tool,  and  the  spiral  spring,  which  is 
required  to  be  quite  stiff,  is  located  as  shown.  A  hole  is  let  into 
the  body  at  D  as  clearance  for  the  angular-faced  tool-post  fixt- 


INTERCHANGEABLE  MANUFACTURING. 


193 


ure  L.  A  channel  F  is  let  into  the  under  side  of  the  pointing- 
tool  E,  with  a  taper  side  at  the  rear  coinciding  with  the  taper 
of  L.  In  first  operation  the  cutting  tool  E  is  allowed  to  pro- 
ject, adjusting  it  by  the  nut  G  slightly  beyond  the  centre  bush- 
ing C.  As  the  box-tool  is  brought  up  to  the  work,  the  wire 
enters  the  hole  D.  As  the  tool  E  begins  to  cut,  the  engager  L 
commences  to  force  the  tool  back,  and  continues  to  do  so  until  it 
ceases  to  cut  and  the  wire  is  pointed  as  shown.  The  turret  is 
then  brought  back,  and  the  spring  causes  the  cutting-tool  to 
resume  its  former  position. 

SCBEW-MACHINE   FIXTUBES   AND   TOOLS   FOE 
MAKING   SPEED-ENDICATOBS. 


The  sketches  herewith  are  of  two  special  chucks  and  of  a 
tapping-machine  which  were  designed  by  Mr.  W.  J.  Parker, 
foreman  of  the  Fulton  Machine  Works,  Broooklyn,  the  chucks 
being  used  for  machining  a  casting  (Fig.  210)  which  forms  the 
body  of  a  speed-indicator  manufactured  by  that  firm.  The  work 
on  this  casting  was  the  boring  out  of  the  large  circular  portion 
A  for  the  revolving  dial-plates  of  the 
indicator ;  the  facing  of  the  bottom  B 
and  of  the  hub  around  which  the  dials 
revolve,  and  the  drilling  of  the  small 
hole  C  in  the  centre  of  this  hub.  All 
this  was  accomplished  in  one  opera- 
tion, after  the  work  had  been  fastened 
in  the  chuck  (Fig.  211).  The  second 
operation  was  the  boring  and  reaming 
of  a  hole  D  (Fig.  210)  for  the  spin- 
dle of  the  indicator  and  the  finishing  of  a  centre  and  thrust 
bearing  for  the  end  of  it  at  E.  Both  chucks  are  used  in  the 
screw-machine  in  conjunction  with  a  set  of  turret-tools  for  each. 
Fig.  21k  shows  the  chuck  used  for  the  first  operation.  It 
consists  of  a  circular  casting  having  a  hub  at  the  back  and  a 
raised  portion  on  its  face  for  holding  the  work.  The  casting  is 
fitted  to  the  screw-machine  spindle,  and  faced  and  bored  to  admit 

the  large  circular  portion  of  the  work  as  shown  at  L,  being  bored 
13 


194 


TOOL-MAKING  AND 


to  a  depth  sufficient  for  the  upper  side  of  the  work  to  project 
slightly  above  the  face  H  of  the  chuck.  The  face  of  the  chuck 
is  milled  away  on  each  side  of  the  square  central  portion  H  so 
that  the  work  may  be  easily  located  or  removed.     J"  is  a  flat 


Fig.  211. 

machine-steel  plate,  located  on  the  face  of  the  chucks  by  two 
dowel-pins  K  K  and  fastened  by  the  four  corner  screws  L  L  L  L. 
This  plate,  while  fastened  to  the  main  casting,  is  bored  suffi- 
ciently to  tightly  clamp  the  edges  of  the  large  circular  portion 
and  for  clearance  for  the  cutting-tools.     Fig.  211  shows  clearly 


VERTICAL  CROSS-SECTION  OF 
CHUCK  AND  WORK 


Fig.  312. 


how  the  work  is  located  and  clamped  on  the  chuck.     The  work 
is  machined  by  the  usual  type  of  turret-tools. 

The  second  operation  is  accomplished  by  the  use  of  the  chuck 
shown  in  Fig  212,  which  is  of  distinctly  different  design  from 
that  of  the  chuck  Fig.  211.     It  is  a  circular  hub-backed  casting, 


INTERCHANGEABLE  MANUFACTURING.  195 

with  a  rather  long,  flat,  projecting  standard  at  II,  fitted,  as  in 
the  other  case,  to  the  screw-machine  spindle  and  having  the  face 
of  H  machined  flat  and  square  with  the  face  of  F.  The  work  is 
located  on  this  projecting  face  at  two  points  by  K  and  J;  also 
at  I  by  a  circular  machine-steel  disk  fitting  within  the  portion  A, 
Fig.  210,  of  the  work  and  fastened  to  the  face  H,  Fig.  213,  of 


Fig.  213. 


FIG.  214. 


the  chuck  by  screws  and  dowel-pins  (not  shown)  and  at  K  by 
the  steel  plate  J,  which,  as  will  be  seen,  is  fastened  by  screws 
and  dowel-pins.  For  clamping  the  work  to  the  chuck  the 
swinging  bracket  and  clamping-screw  N  are  used,  the  construc- 
tion of  which  is  shown  in  the  cross-section  view  of  Fig.  214,, 
where  the  work  is  shown  fastened  upon  the  chuck.  The  work 
machined  in  these  chucks  is,  needless  to  say,  perfectly  inter- 
changeable. 

METHOD   FOE    FINISHING   DUPLICATE    WOEK   IK 
THE   SCEEW-MACHINE. 


The  special  tools  and  fixtures  here  described  were  designed 
for  the  screw-machine,  and  consisted  of  an  improved  driver 
for  the  work ;  a  special  arrangement  of  lathe  centres,  and  a  form- 
ing-tool and  holder  which  will  duplicate  work  without  chatter- 
ing and  without  regard  to  pressure  applied  by  the  operator. 

The  particular  piece  of  work  for  which  these  tools  were  de- 
signed is  shown  in  two  views  in  Figs.  215  and  216  and  is  called 
a  "goose-neck."     It  is  a  brass  casting,  and  is  finished  at  the 


196 


TOOL-MAKING  AND 


taper  end  marked  A.  Before  finishing  this  surface,  the  castings 
were  centred  at  C,  and  chamfered  slightly  on  the  inside  at  B. 
The  first  fixture  made  for  the  finishing  operation  was  the  special 

B  B 


Fig.  215. 


Fig.  216. 


chuck,  a  cross-section  of  which  is  shown  in  Fig.  217.  The  body 
of  the  chuck  was  a  casting  of  the  shape  shown,  and  was  bored 
out  at  C  C.  It  was  first  chucked  in  the  lathe  and  bored  out  and 
threaded  at  G  G  to  fit  the  spindle  of  the  screw-machine,  and  then 


Fig.  217. 


squared  up.  It  was  then  faced  and  the  rim  trued.  A  hole  was 
bored  and  threaded  at  D  to  admit  the  centre  E,  which  was  fin- 
ished with  a  shoulder  at  jP  so  as  to  allow  it  to  rest  squarely 


INTERCHANGEABLE  MANUFA  CT UE1NG. 


197 


against  the  face  of  the  chuck.  A  square  hole  was  then  let 
through  the  face  of  the  chuck  to  admit  the  driver  I,  which  was 
made  of  f -iuch  round  tool  steel  and  bent  as  shown,  and  the  end  I 
finished  to  a  smooth  fit  within -the  hole  J.  The  round  portion  R 
of  this  driver  was  long  enough  to  allow  it  to  extend  clear  through 
the  screw-machine  spindle,  and  was  connected  to  the  wire-feed 
lever.  This  manner  of  connecting  the  driver  allowed  it  to  be 
forced  out  and  in,  thereby  permitting  the  work  to  be  located  on 
the  centres,  and  removed  when  finished  without  stopping  the 
machine. 

As  the  edge  B  of  the  work,  Fig.  215,  gives  a  very  narrow  bear- 
ing for  the  tail -centres,  and  as  the  work  revolved  very  fast,  it 


FIG.  218. 


was  not  practical  to  adopt  the  ordinary  centre,  as  there  was  a 
tendency  for  the  end  of  the  work  to  run  hot  and  burr  up.  So,  to 
overcome  this,  the  special  sleeve  and  running-centre,  shown  in  a 
cross-sectional  view  in  Fig.  218,  were  made.  This  fixture  consists 
of  a  sleeve  which  was  first  bored  out  and  tapped  at  the  back  end 
for  the  centre  end-thrust  screw  M.  It  was  then  placed  on  an 
arbor  and  turned  taper  on  the  outside  to  fit  the  tail -stock,  which 
had  been  fitted  to  the  screw-machine.  The  end-thrust  screw  M 
was  then  made  with  thrust  end  finished  flat,  hardened  and  pol- 


198 


TOOL-MAKING  AND 


islied.  It  was  then  screwed  tightly  into  the  sleeve.  The  run- 
ning-centre K  was  then  made  of  tool  steel  and  finished  to  fit  the 
sleeve  smoothly,  and  tapered  at  L  and  the  point  rounded.  This 
end  was  then  hardened  and  polished.  After  an  oil-hole  had 
been  let  into  the  sleeve  and  the  inside  polished  smooth,  the  fixt- 
ure was  finished. 

As  the  manner  of  finishing  the  formed  surface  of  the  work  is 


Fig.  219. 

distinctly  different  from  tne  usual  methods  in  general  use,  and 
as  the  forming-tool  and  holder  are  of  a  novel  design,  they  are 
worthy  of  a  detailed  description. 

By  referring  to  Figs.  219  and  220,  in  which  a  plan  and  side 
view  respectively  of  the  tool  and  holder  are  shown,  the  following 


P^O 

vl 

k(St 

p 

~~" i 

Ms 

\                                             SIDE  VIEW 

FIG.  220. 

description  of  them  will  be  intelligently  understood.  The  holder 
is  a  casting  of  the  shape  shown  at  F,  and  was  dovetailed  on  the 
bottom  and  fitted  to  the  cross-slide  of  the  screw-machine  and 
equipped  with  a  rack  to  mesh  with  the  feed-gear,  as  shown  at 
N,  Fig.  218.     The  portion  for  holding  the  forming-tool  Q,  Fig. 


INTERCHANGEABLE  MANUFACTURING .  199 

219,  was  then  planed  dovetail,  slanting-  upward  to  the  degree 
shown  in  the  side  view  of  Fig.  220.  A  hole  was  then  drilled 
and  tapped  through  the  lug  B  to  admit  the  tool  adjusting-screw 
8.  Two  headless  set-screws  T  T  were  also  let  into  the  side,  as 
shown.  The  forming-tool  Q  was  of  f -inch  flat  tool  steel,  finished 
all  over,  and  fitted  to  the  holder  as  shown.  The  shape  required 
was  then  worked  out  on  the  face  for  its  entire  length,  and  finished 
in  the  milling-machine  with  a  special  fly-cutter,  as  shown  in  Fig. 
218.  The  cutting-face  of  the  tool,  V  V,  Fig.  219,  was  sheared 
off  to  the  angle  shown,  so  as  to  allow  the  work  to  be  cut  gradu- 
ally. The  tool  was  then  hardened  and  drawn  to  a  light-straw 
temper,  and  the  cutting-face  ground  and  oil-stoned  to  a  keen 
edge.  The  fixture  and  tools  were  now  complete  and  ready  for 
work. 

The  parts  were  set  up  in  the  screw -machine  in  the  relative 
positions  shown  in  Fig.  218.  The  machine  was  started,  and  the 
driver-lever  pulled  back,  thereby  drawing  the  driver  I  into  the 
chuck.  The  work  was  then  placed  on  the  centres,  with  the  por- 
tion C  on  the  chuck-centres  and  the  face  end  on  the  running-cen- 
tre K.  The  driver-lever  was  then  pulled  out,  causing  the  driver 
1  to  emerge  and  drive  the  work,  the  running-centre  L  travelling 
with  it.  The  handle  O  of  the  cross-slide  was  then  pulled  down 
and  the  forming-tool  presented  to  the  work,  cutting  the  face 
gradually.  And  as  each  portion  of  the  work  was  reduced  and 
finished,  that  point  of  the  tool  passed  the  centre  and  came  out 
under  the  work;  and  as  the  whole  face  was  finished,  the  entire 
cutting-face  of  the  tool  passed  free  and  clear  of  the  work.  The 
driver  I  was  then  drawn  in  (without  stopping  the  machine)  and 
the  tail-centre  drawn  back  and  the  work  removed.  Another  cast- 
ing was  then  located  ou  the  centres,  the  driver  sent  out,  and  the 
work  finished  as  before. 

As  will  at  once  be  seen,  the  use  of  the  special  chuck  reduces 
the  time  necessary  to  locate  the  work  on  the  centres,  and  remove 
it  when  finished,  to  the  minimum.  And  the  running  tail-centre 
eliminates  the  possibility  of  the  work  running  hot  and  burring, 
as  well  as  the  waste  of  time  in  adjusting  the  centre  against  the 
work.  The  methods  of  finishing  formed  surfaces  by  means  of 
tools  of  the  design  shown  is  meeting  with  more  favor  all  the 


200 


TOOL-MAKING   AND 


time,  as  very  wide  and  intricate  forms  can  be  duplicated  on 
round  work  without  any  trouble.  Another  thing,  by  the  use  of 
this  tool  work  can  be  finished,  one  piece  in  exact  duplication  of 
the  other. 


FIXTUEES   FOE   FOEMIKG   PIECES   OF   IBEEGULAE 

OUTLINE. 

In  the  preceding  chapter  a  fixture  for  forming  pieces  of  ir- 
regular outline  from  the  bar  was  described,  which  fixture  was 
adapted  to  work  having  considerable  stock  to  be  removed.  The 
tool  here  to  be  described  consists  of  a  similar  fixture  for  use  in 
the  screw-machine  for  forming  irregularly  shaped  surfaces,  but 
from  individual  castings  instead  of  from  the  bar,  and  in  which 
less  metal  is  to  be  removed. 

The  article  for  which  this  device  was  used  is  an  improved  gas- 
stove  cock  made  in  two  parts,  each  of  which  is  of  irregular  exte- 
rior outline,  as  shown  in  the  longitudinal  sectional  view  in  Fig. 


Fig.  221. 

221.  The  length  of  the  assembled  cock  over  all  is  4f  inches, 
and  the  pieces  are  composition  castings  with  the  holes  K  and  F 
cored  in  them.  Certain  preliminary  minor  operations  are  neces- 
sary on  both  parts  1  and  2  before  the  forming -cutter  is  used,  in 
order  to  form  the  threaded  hub  0  G  on  part  1  and  the  threaded 
recess  B  B  in  part  2  for  a  means  of  definitely  locating  them  on 
the  face-plate,  which  operations  will  be  described  later  on. 

The  forming-cutter  used  for  obtaining  the  irregular  outline 
surface  is  one  of  the  circular  forming  type  of  cutters,  which  is 
shaped  entirely  around  its  exterior  surface,  the  cutting-edge 
being  produced  by  milling  out  a  longitudinal  groove  on  its  exte- 
rior as  shown  in  Figs.  222  and  228.  This  is  the  type  of  cutter 
that  may  be  ground  and  reground  almost  indefinitely  without  al- 


INTERCHANGEABLE  MANVFA  CT  UBING. 


201 


tering  the  shape  of  its  cutting -edge  if  the  body  of  the  cutter  is 
properly  shaped.  The  cutter  shown  in  Figs.  222  and  223,  which 
represent  the  cutter  used  for  machining  the  surface  of  part  2  of 
the  gas-cock,  was  made  of  tool  steel,  which  was  annealed  and 


bored  out  at  D  and  a  keyway  let  down  through  the  entire  length 
at  C,  after  which  it  was  driven  on  to  an  arbor  and  the  ends  fin- 
ished as  shown  at  B  B,  and  the  required  shape  turned  on  to  the 
outside  from  end  to  end  to  templet,  as  shown.     The  finishing  of 


Fig.  223. 


this  forming  was  done  very  carefully  by  first  roughing  it  out  with 
the  usual  lathe-tools  and  then  using  a  variety  of  hand-tools  to 
finish  it  to  shape.     Especial  care  was  taken  to  get  its  entire  sur 
face  smooth  and  free  from  marks,  and  it  was  finished  to  a  dead- 


202 


TOOL-MAKING   AND 


smooth  finish  by  means  of  lapping  with  stick,  emery,  and  oil. 
This  was  necessary,  as  the  work  was  required  to  have  a  high  fin- 
ish after  being  machined,  and  as  the  manner  in  which  the  cutter 
was  presented  to  the  work  allowed  of  its  burnishing  the  same  as 
soon  as  the  cutting-edge  had  removed  the  required  amount  of 
stock  and  passed  the  centre. 

After  being  lapped,  the  cutter  was  set  up  in  the  milling-ma- 
chine and  a  groove  milled  out  to  form  the  cutting-edge  from  E  G 


Fig.  224. 


to  F,  as  shown  in  Fig.  222,  it  being  milled  on  a  spiral,  as  shown 
in  the  face  view,  Fig.  222,  so  as  to  cause  the  cutter  to  remove  the 
stock  progressively.  In  fact,  the  cutting-edge  of  the  cutter  was 
finished  in  the  same  manner  as  a  wide-face  milling-cutter,  except 
that  the  spiral  was  not  quite  as  abrupt.     After  finishing  the  cut- 


FIG.  225. 


ting-edge  as  shown,  the  cutter  was  carefully  hardened  and  drawn 
to  a  very  light-straw  temper,  thus  leaving  it  as  hard  as  is  con- 
sistent with  reliable  cutting. 

The  cutting-edge  was  then  ground  on  the  cutter-grinder,  and 
carefully  oil-stoned  so  as  to  present  a  smooth,  keen  edge  for  its 
entire  length.  The  holder,  or  bracket,  shown  in  Fig.  223,  which 
supports  the  cutter  and  its  cutter-stud  H,  Fig.  225,  was  made 
from  a  forging  with  the  shank  N  finished  to  fit  the  large  tool-post 
of  the  turret-lathe.  The  way  in  which  the  cutter  is  mounted  in 
the  holder  is  shown  in  Fig.  223,  which  shows  a  top  view  of  the 


INTERCHANGEABLE  MANUFACTURING. 


203 


cutter  in  place  upon  its  stud  H  and  the  hand-lever  R  mounted 
upon  the  projecting  end  M  of  the  stud. 

The  manner  of  using  the  fixture  may  be  understood  from  Figs. 


Fig.  226. 


226  and  227 ;  Fig.  226  showing  a  front  view  of  both  fixture  and 
work  in  position,  the  face-plate,  the  turret-head,  and  Fig.  227  an 


FIG.  227. 


end  view  toward  the  face-plate  to  indicate  the  manner  in  which  the 
cutting-edge  of  the  cutter  is  presented  to  the  work.  In  machin- 
ing the  work  the  handle  of  the  cross-slide  is  moved  by  the  left 


204 


TOOL-MAKING   AND 


hand  of  the  operator  until  the  cutting-edge  of  the  tool  is  in  the 
position  against  the  work  shown  in  the  end  view,  Fig.  227,  and 
held  there  with  the  help  of  the  feed-screw  of  the  cross-slide, 
while  wTith  the  right  the  lever  of  the  forming-tool  is  pulled  for- 
ward. As  the  cutter  is  slowly  revolved  in  the  holder  by  the 
pressure  on  the  lever,  it  cuts  and  removes  the  required  amount 
of  stock  progressively,  due  to  its  spiral  cutting-edge,  and  as  the 
cutting-edge  passes  the  centre  line  the  friction  of  the  finished  por- 
tions of  the  work  revolving  rapidly  against  the  exterior  of  the 
cutter  produces  a  high  finish  of  its  entire  surface. 

The  cutter  which  was  used  for  milling  part  1  of  the  gas-cock, 
Fig.  221,  is  shown  in  front  view  and  section  in  Figs.  228  and  229, 
and  in  end  view  in  Fig.  224.  This 
cutter  was  made,   tempered  and 

CUTTER 


Fig.  228. 


ground  exactly  the  same  as  was  the  other,  and  its  method  of 
use  in  removing  the  stock  and  obtaining  the  burnish  or  polish  is 
identical. 

In  connection  with  the  finishing  of  these  gas-stove  cocks  other 


Q\2T_~Z 


Fig.  230. 


fixtures  were  used  which  may  be  of  interest.     In  forming  the 
threaded  hub  C  0,  parti,  Fig.  221,  a  pair  of  slip-jaws  for  a  regu- 


INTERCHANGEABLE  MANUEA  CTUBING. 


205 


lar  two-jaw  chuck  was  used  for  chucking  the  work  while  ma- 
chining. These  jaws,  which  are  shown  in  Fig.  230,  are  of  cast- 
iron  ;  are  finished  dovetail  to  drive  into  the  jaws  proper  of  the 
chuck,  and  are  located  in  the  proper  relative  positions  by  means 
of  a  taper-pin  at  B.  The  way  in  which  these  jawrs  are  con- 
structed and  finished  to  allow  of  locating  the  work  as  shown  is 

evident  from  the  sketch.  The  facing 
of  the  surface  M  M  is  accomplished  by 
means  of  a  hollow  mill,   which  differs 


1  R?T 


;__r" — i 


Fig.  231. 


FIG.  233. 


from  the  type  generally  used  in  that  it  has  fifteen  teeth.  The 
hub  G  C  is  finished  by  the  mill  also,  the  thread  being  cut  by 
means  of  a  collapsible  die. 

In  Figs.   231  and  232   are  shown   the   slip-jaw\s  which  are 
used  for  the  first  and  third  operations  on  part  2,  Fig.  221,  which 


FIG.  233. 

contains  the  gas-cock  proper.  These  two  sets  of  jaws  are  con- 
structed similar  to  the  first  set,  Fig.  230,  and  are  used  in  the 
same  way.  The  part  shown  at  A,  Fig.  232,  is  for  holding  the 
casting  for  part  2  while  the  surface  at  A  A  is  being  faced,  the 


206 


TOOL-MAKING   AND 


seat  for  the  rubber  washer  let  in  at  D  D,  and  the  hole  at  B  bored 
and  tapped  to  fit  the  threaded  hub,  part  1.  The  other  set  of 
jaws  is  used  for  holding  part  2  after  being  machined  all  over, 
when  the  taper  hole  for  the  key  J  is  being  let  in  at  8,  Fig.  231, 
which  shows  the  work  located  within  the  jaws  and  the  hole 


fig.  334. 

drilled  at  8.  This  hole,  after  being  centred  in  the  usual  man- 
ner, is  reamed  to  the  required  taper  by  means  of  a  "floating" 
reamer  of  the  usual  type. 

For  turning  the  washer-seat  at  D  D,  in  part  2,  the  special  ec- 
centric box-tool  shown  in  Fig.  233  was  used,  which  is  of  an  inter- 
esting construction.  J.  is  a  holder  or  frame,  made  of  cast-iron, 
which  a  shank  portion  at  jB  turned  to  fit  the  hole  in  the  turret. 
C  is  an  eccentric  bushing  located  within  the  holder  by  the  set- 
screw  H;  G  the  cutting-tool ;  F  the  lever  by  which  it  is  manipu- 
lated.    The  depth  of  cut  is  regulated  by  adjusting  the  lever  stop- 


INTERCHANGEABLE  MANUFACTURING.         207 

screw  J,  which  is  let  into  the  projecting  lug  K  as  shown  iu  the 
end  view  of  the  tool.  In  using  this  fixture,  after  the  tool  G  has 
beeu  entered  into  the  cored  hole  in  the  work  the  required  dis- 
tance, the  lever  _Fis  raised  slowly  until  it  rests  against  the  stop- 
screw  J,  which  determines  the  proper  depth  of  cut,  then  it  is 
dropped  and  the  tool  backed  out. 

A  novel  drill-jig  was  designed  for  use  in  boring  the  six  in- 
clined air-draught  holes  leading  into  the  combining-chamber  F 
in  part  2  of  the  gas-cock.  The  jig  is  shown  in  plan  and  in 
sectional  elevation  in  Fig.  234,  with  the  work  in  place.  As  is 
shown,  these  six  holes  are  required  to  be  drilled  at  an  angle  with 
the  axis  of  the  casting,  and  also  to  be  equidistant,  and  an  inter- 
esting design  is  the  result.  A  is  the  body  casting  of  the  jig, 
which  is  machined  on  the  base  at  D,  and  also  on  both  sides  of 
the  projection  B,  to  an  angle  Y  with  the  base,  as  shown.  The 
indexing-device  X  and  the  locating-stud  for  the  work  are  of  tool 
steel,  hardened  and  ground.  There  are  six  equally  spaced 
notches  in  the  index-plate  which  coincide  in  shape  with  the  end 
H  of  the  index-pin  R  and  locate  the  work  for  the  six  different 
holes.  The  drill-bushing  Pis  located  as  shown  in  the  swing-lid 
J,  which  is  hinged  within  the  two  sides  K  K  of  the  body  casting 
A  by  means  of  the  pipe  L.  A  hole  0  in  the  lid  allows  clearance 
for  the  work  when  located  in  the  jig ;  all  that  is  necessary  for 
removal  being  to  swing  the  bushing-lid  J  back  and  unscrew  the 
work  off  the  locating-stud. 


CHAPTER  XIV. 

The  Construction  and  Use  of  Boring  Fixtures  and 
Similar  Tools. 

THE   DRILL-PRESS  AND   BOEING  FIXTURES. 


One  of  the  things  that  make  the  large  drill-press  a  valuable 
machine  tool  is  its  adaptability  for  performing  accurate  opera- 
tions in  the  production  of  interchangeable  parts  by  the  use  of 
simple  and  often  inexpensive  fixtures.  In  fact,  I  do  not  hesitate 
to  state  that  it  runs  the  turret-lathe  a  close  second  for  the  place 
of  the  most  rapid  and  economical  producer  in  the  shop. 

Now  aside  from  the  adaptability  of  the  drill-press  for  jig- 
drilling,  there  is  any  quantity  and  variety  of  work  recpairing  to 
A  a 


Fig.  235. 

be  bored  which  can  be  handled  to  good  advantage  on  this  ma- 
chine; and  in  this  chapter,  among  other  things,  I  will  devote 
considerable  space  to  describing  and  illustrating  types  for  bor- 
ing-fixtures which  were  designed  to  be  used  on  the  drill-press 
and  have  worked  well  in  practice,  and  their  presentation  will 

208 


INTERCHANGEABLE  MANUFA  GTURING. 


209 


prove  suggestive  for  others.  The  practical  points  for  the  design- 
ing and  construction  of  the  fixtures  will  assist  the  tool -maker  in 
the  attainment  of  the  desired  results  with  ease,  and  dispense 
with  much  unnecessary  labor  and  expense. 

BOEING   AND   FACING   FIXTURE   FOR   "SEXTIT" 
CASTINGS. 

The  casting  shown  in  sketch  Fig.  235  has  six  radiating  cylin- 
ders, each  with  a  cored  hole  through  it.  It  was  necessary  to 
bore  and  finish  the  holes  in  line  with  the  central  hole  E,  and  the 


F  a.  236. 

opposite  holes  in  line  with  each  other.  The  jig  shown  in  Figs. 
236,  237,  and  238  was  made  for  the  job. 

The  centre  hole  was  first  bored  and  counterbored,  and  the 
front  faced  at  D.  It  was  then  driven  on  to  an  arbor  and  the 
back  faced  at  F. 

The  jig  consists  of  an  angle  casting  with  a  boss,  faced  on  the 
back  at  H  and  I  respectively,  also  a  back  extension  on  the  top. 
After  being  planed  on  the  bottom  and  dovetailed  for  the  bush- 
ing-plate K,  bosses  H  and  L  were  faced  and  the  top  was  planed 
and  dovetailed  for  the  upper  bushing -plate  J.  It  was  also  dove- 
tailed on  the  side  for  the  index-pin  bracket  W,  and  the  hole 
bored  for  the  clamping- stud  0. 

The  two  bushing-plates  K  and  J,  of  machine  steel,  were  fitted 

tightly  into  the  dovetailed  channels,  located  in  line  with  each 
14 


210 


TOOL-MAKING   AND 


other,  and  fastened.  The  centres  of  the  holes  for  the  bushings 
U  and  V  were  located  by  setting  the  casting  on  its  side  on  a  sur- 
face-plate and  striking  a  line  from  the  centre  of  the  hole  for 
the  stud  0  to  the  plate  J  and  K  with  the  help  of  a  Brown  & 
Sharpe  height-gauge.  The  centre  in  the  opposite  direction,  the 
distance  from  the  face  of  the  boss  H  to  the  centre  of  the  bushings 
TJ  and   V  was  also  marked.     The  plates  J  and  K  were  then 


FIG.  237. 

driven  out  and  the  holes  were  bored  and  the  two  bushings  U  and 
V  were  made  and  forced  in.  The  plates  were  then  returned  to 
their  respective  positions. 

The  index-plate  N  and  clamping-stud  0  are  in  one  piece.  It 
was  a  mild -steel  forging.  The  plate  had  on  its  periphery  six 
equidistant  square  notches.  The  index-pin  bracket  W,  a  cast- 
ing, was  then  fitted  to  drive  tightly  into  the  dovetailed  channel 
in  the  side  of  the  angle-plate.  The  hole  for  pin  X  was  then 
bored. 

The  pin  was  made  of  tool  steel,  the  end  fitting  the  square 
notches  in  the  index-plate,  and  slightly  rounded  to  enter  .the 
notches  easily.     A  stiff  helical  spring  V  was  made  and  also  a 


INTERCHANGEABLE  MANUFACTURING.         211 

hole  was  drilled  in  the  pin  X  for  the  spring  cross-pin.     After 
the  handle  Z  was  made  all  the  parts  were  assembled. 

All  that  remained  to  complete  the  rig  was  the  boring-bar,  Fig. 


Fig.  233. 


5: 


239,  and  the  two  sets  of  cutters  B  B  and  I).  This  bar 
was  of  machine  steel,  turned  taper  at  the  end  to  fit  the 
drill-press  spindle,  and  for  the  rest  of  the  length  a  run- 
ning fit  in  the  bushings  U  and  V.  The  bar  was  small 
enough  to  clear  the  cored  holes.  Two  sets  of  cutters 
were  made,  one  set  for  roughing  and  the  other  for  finish- 
ing. These  cutters  were  fastened  in  the  bar  by  taper- 
keys.  The  jig  was  strapped  to  the  table  of  a  large 
drill-press.  The  index-plate  N,  with  the  pin  X  in  one 
of  the  notches,  was  clamped  and  a  casting  to  be  bored 
clamped  in  position  ou  it,  so  that  the  boring-bar  would 
be  as  nearly  central  as  possible  in  the  cylinder  to  be 
bored.  The  roughing -cutters  were  then  fastened  in  the 
bar  and  the  holes  were  bored.  These  cntters  were  then 
removed  and  the  finishing  pair  were  substituted  and  the 
holes  were  finished. 

After  all  six  holes  were  bored,  which  required  only  three  ad- 
justments of  the  index-plate,  both  ends  of  all  six  cylinders  were 
faced  by  using  the  cutters  D.     All  the  eastings,  of  which  there 


::1 


:9 


Fig.  239. 


212 


TOOL-MAKING   AND 


were  a  large  number,  were  bored  and  faced  in  this  manner,  and 
were  found,  when  assembled  with  other  parts,  to  interchange  per- 
fectly. 


DEILL-PEESS   BORING 


EIG    FOE   INTERCHANGEABLE 
WOEK. 


The  tools  described  in  the  following  were  used  for  boring  and 
finishing  the  cast-iron  shell  shown  at  B,  Figs.  242-243.  The  part 
finished  is  shown  at  F,  being  a  seat  for  a  brass  ring  that  was  to 
fit  in  snugly  so  as  to  be  air-tight,  and  it  was  also  necessary  to 
have  them  all  exactly  the  same  size.  The  shells  were  being  made 
in  lots  of  five  hundred. 

The  jig  for  holding  the  shells  is  also  shown  in  the  two  views. 
A  is  the  jig,  of  cast-iron,  which  was  faced  off  on  the  bottom  and 


Fig.  240. 


Fig.  241. 


strapped  true  on  the  face-plate  of  the  lathe  by  the  ears  E  E.  It 
was  then  bored  out  to  the  shape  and  size  of  the  shells  at  G  and  a 
hole  bored  in  the  bottom  for  the  plug  I).  It  was  then  milled  out 
at  three  places  on  the  top  to  give  the  three  wings  D  clearance. 
The  plug  D,  made  of  machine  steel,  was  then  turned  and  finished 
so  as  to  just  fit  the  inside  of  the  shells,  as  shown,  and  then  driven 
into  the  jig  A,  projecting  through  at  the  bottom,  as  shown.  The 
part  projecting  through  just  fitted  the  centre  hole  in  the  table  of 
the  large  drill-press  in  which  the  boring  was  done. 

Figs.  240  and  241  show  the  holder  and  tools  for  boring,  which 
were  made  in  the  following  manner:  G  is  the  holder  proper, 
made  of  cast-iron  with  three  wings,  to  allow  of  using  three  cut- 


INTERCHANGEABLE  MANUFACTURING. 


213 


ting-tools,  as  we  found  after  experiment  that  this  number  worked 
the  best.  The  tool  was  first  chucked  and  the  hole  I  bored  and 
reamed  for  the  shank  J.  It  was  then  removed  and  the  shank  J 
turned  and  finished  to  fit  the  spindle  of  the  drill-press,  with  a 
shoulder  at  M.     The  other  end  was  turned  down  so  as  to  drive 


Fig.  342. 

snugly  into  the  holder  G.  The  assembled  tool  was  then  put  be- 
tween centres  in  the  milling-machine  and  the  holes  for  the  tools 
K  K  JSTwere  laid  out  and  drilled  and  reamed.  It  was  then  taken 
out  and  the  holes  for  the  set-screws  L  L  L  were  drilled  and 


Fig.  243. 

tapped.  Next,  the  three  cutting-tools  were  made  and  finished  as 
shown.  These  were  hardened  and  drawn,  and  inserted  in  their 
places,  which  completed  the  boring-tool. 

A  piece  of  steel  the  size  of  the  hole  in  the  table  was  chucked 
in  the  drill-press  and  inserted  in  the  hole  in  the  table,  which  was 


214  TOOL-MAKING   AND 

locked,  thereby  setting  it  true  with  the  spindle.  The  jig  A  was 
strapped  on  the  table  by  the  ears  E  E,  with  the  lug  D  in  the 
centre  hole,  and  the  work  put  in,  resting  on  the  bottom  as  shown 
in  the  sketch.  The  plug  D  centred  it  and  the  three  pins  not 
shown  entered  the  holes  in  the  ears  B,  which  prevented  it  from 
truing.  The  holder,  Fig.  240  was  then  set  into  the  spindle  and 
the  tools  set  to  cut  exactly  the  right  diameter,  and  after  being  run 
down  to  the  proper  depth  the  spindle-stop  was  set. 

The  rest  was  plain  sailing  and,  except  for  stopping  to  sharpen 
tools  at  long  intervals,  the  pieces  were  turned  out  very  rapidly 
(each  and  every  one  alike)  at  a  very  small  cost  and  much  better 
and  cheaper  than  they  could  have  been  done  by  any  other  prac- 
tical means.  The  saving  in  the  first  one  hundred  shells  paid  for 
the  cost  of  the  tools. 

A  SPECIAL   MACHINE   FOE   BOEING   BEACKETS  AND 
SPINDLE-HEADS. 

When  constructing  sensitive  drill- presses  of  from  one  to  five 
spindles,  the  boring  of  the  hole  for  the  spindle  in  the  upper 
bracket  and  the  spindle-head  is  done  after  all  the  other  work  has 
been  done  and  the  upper  column,  upper  bracket,  and  spindle - 
head  assembled.  In  the  following,  Figs.  244  to  247,  I  show  and 
describe  a  machine  which  was  designed  specially  for  doing  this 
work — that  is,  for  boring  the  spindle  holes  in  drills  of  from  one 
to  five  spindles. 

As  this  tool  or  machine  is  designed  to  be  used  and  fastened 
directly  to  the  columns  while  the  holes  are  being  bored,  the  pos- 
sibility of  error  in  the  alignment  of  the  spindle  when  assembled 
is  reduced  to  a  minimum ;  also,  the  manner  of  locating  and  fast- 
ening the  tool  to  the  work  while  in  operation  is  as  reliable  and 
positive  as  could  very  well  be  devised  for  the  class  of  work  for 
which  it  is  used.  The  tool  consists  of,  first,  a  body  casting  iT  of 
the  shape  and  design  shown  in  Figs.  244,  245,  and  246.  The 
driving-spindle  Y,  with  a  tight  and  a  loose  pulley,  W  and  IF  IF 
respectively,  at  one  end,  and  a  bevel-gear  V  at  the  other.  In 
the  head  Q  is  the  spindle -driving  gear  with  the  two  driving- 
pins  B  B  ;  0  is  the  spindle  or  cutter-bar,  and  8  the  bar-driver, 


INTERCHANGEABLE  MANUFACTURING. 


215 


while  H  is  the  means  for  feeding  the  pinion,  which  engages  the 
rack,  on  the  bar  or  spindle.  The  sets  M  M  31 M  in  the  lugs 
which  project  above  the  face  of  the  plate  or  body  casting  shown, 
are  for  bracing  and  holding  securely  the  brackets  and  heads 


III1 

nn 

pi 

«l 

||i  III 

8inRF 

q  nR 

while  they  are  being 
bored.  P P,  in  the  spin- 
dle O,  are  the  cutters, 
while  the  adjustable 
angle  pieces  J  J,  and 
the  clamping-levers  L  L, 
are  for  fastening  the  rig 
true  and  positively  to 
the  columns  while  in  operation. 

The  means  and  ways  called 
into  use  in  the  construction  and 
successful  operation  of  the  boring- 
rig  are  of  interest  and  they  will 
be  described  in  turn.  After  the 
body  casting  A  was  secured,  the 
first  thing  done  was  to  bore  and 
finish  the  hole  through  the  head 
B  and  the  tail  0.  The  size  of  the 
hole  in  the  head  B  is  shown  clearly 
in  the  detail  drawing  in  Fig.  247. 
The  boring  was  accomplished  by 
strapping  the  casting  lengthwise 

on  an  angle-plate,  which,  in  turn,  was  fastened  to  the  table  of  the 
large  drill-press — first  drilling  a  clearance-hole  through  both 
head  and  tail  large  enough  to  allow  of  the  boring-bar  (used  for  fin- 
ishing), being  entered  through  both  the  head  B  and  the  tail  C,  get- 


Fig.  244. 


216 


TOOL-MAKING   AND 


ting  them  approximately  central  in  each.  A  bushing  which  just 
fitted  the  hole  in  the  centre  of  the  drill-press  table,  and  within 
which  the  bar  would  fit  snugly,  was  then  tapped  in  and  located  in 
the  table.  This  was  for  strengthening  and  centring  the  boring- 
bar.  The  bar  and  cutters  were  then  centred,  the  table  clomped 
in  position,  when  the  holes  were  bored 
and  finished  to  size  required  in  each.  The 
front  of  the  head  B  was  then  faced,  by 
using  a  cutter  of  sufficient  width. 

We  were  now  ready  to  plane  off  the 
base.  This  was  done  by  first  securing  two 
"  V"  blocks,  with  a  tongue  on  the  bottom 
of  each,  by  which  they  were  set  dead  cen- 
tral to  each  other  (by  entering  the  tongue 
into  the  central  slot  in  the  planer  bed), 
and  a  piece  of  turned  steel  long  enough 
to  extend  about  six  inches  outside  of  each 
of  the  holes  bored,  and  to  fit  each  of  them 
snugly.  The  casting  was  then  set,  and 
secured  by  resting  the  bar  on  the  "V" 
blocks,  and  clamping  and  casting  at  either 
end.  This  made  the  alignment  of  the  hole 
at  a  true  right  angle  with  the  planer-head. 
The  base  of  the  casting  A  was  then  planed 
perfectly  fiat  for  its  entire  length,  as  far 
as  the  lugs  or  extensions  F  F,  which  were 
planed  to  the  angle  shown  at  67,  or  the 
same  as  that  of  the  columns  on  which  it 
was  to  be  used.  The  distance  from  the 
centre  of  the  hole  in  the  head  B  and  the 
tail  G  to  the  extreme  point  of  the  planed 
angle  at  G  was  exactly  one-half  of  the 
width  of  the  dovetailed  slide  of  the  columns.  This  done,  the 
casting  is  removed  from  the  planer  and  reset  on  the  drill-press 
by  strapping  to  an  angle-plate,  and  the  hole  bored  in  D  for  the 
driving-shaft  X,  care  being  taken  to  get  it  at  right  angles  and 
central  with  the  hole  in  the  head  and  tail,  and  the  necessary  dis- 
tance from  it,  to  alloAv  of  the  two  bevel -gears  C/"and  Q  meshing 


Fig.  245. 


1NTEJRGHA  NGEABLE  MANUFA CTUBING. 


217 


correctly.  This  hole  is  bored  sufficiently  large  to  allow  of  a 
machine-steel  bushing  V  being  driven  in  to  act  as  a  bearing. 
The  hole  for  the  rack-pinion  in  the  bosses  E  E  is  also  bored  and 


Fig.  246. 

finished,  to  the  size  required  at  each  end,  in  this  setting,  boring 
the  large  part  deep  enough  to  allow  of  the  pinion  being  in- 
serted therein.  The  casting  is  then  removed  and  the  holes 
drilled  and  tapped  for  the  four  set-screws  M,  and  also  the  slots 
for  the  adjusting-  and  clamping-levers  L  L  let  in  at  K  K,  as 
shown. 

The  driving-shaft  T  was  then  made  and  finished,  as  shown ; 
as  were  the  two  pulleys  W  and  W  W.  The  gear  U  is  keyed  on 
and  the  collar  X  keeps  the  loose  pulley  W  W  in  position.     This 


Fig.  247. 


being  done,  we  were  ready  to  finish  the  construction  of  the  head, 
and  spindle  or  boring-bar.     This  is  clearly  shown  in  the  cross- 


218  TOOL-MAKING  AND 

sectional  drawing  in  Fig.  247.  The  first  thing  done  was  to 
finish  the  spindle  or  boring-bar  0.  This  was  turned,  as  will  be 
seen,  with  a  collar  at  (2)  to  rest  against,  and  also  threaded  for 
the  two  jam-nuts  (5).  The  rack  (4)  is  fastened  to  the  centre  of 
the  sleeve  by  letting  it  into  a  channel  ^-inch  deep  in  the  sleeve. 
The  large  shoulder-bushing  is  then  made,  and  is  first  bored  and 
finished  to  the  same  diameter  as  sleeve  (3),  after  which  it  is 
placed  on  a  mandrel  and  turned  to  the  shape  on  the  outside,  as 
shown,  there  being  two  shoulders,  one  to  rest  against  the  face 
of  the  head  B  and  the  other  to  rest  within  the  counterbored 
portion  of  the  gear,  the  smallest  diameter  fitting  the  hole  in  the 
head  B  tightly,  the  projecting  end  of  the  portion  being  threaded 
for  the  two  jam-nuts  N  N.  The  turning  of  the  shoulders,  as 
shown,  allows  of  easily  locating  the  gear  Q,  which  revolves  free 
around  the  outside  of  the  bushing. 

It  is  now  necessary  to  plane  the  channel  (10)  through  the 
entire  length  of  the  bushing,  as  a  clearance  way  for  the  rack  (4). 
This  is  done  as  shown,  breaking  completely  through  the  bush- 
ing for  the  length  of  its  smaller  diameter,  and  to  the  same  depth 
in  its  larger  diameter,  the  stock  left  here  being  sufficient  to 
hold  and  keep  the  bushing  from  expanding  or  warping  from  its 
original  shape.  rIVo  holes  are  drilled  in  the  face  of  the  gear  Q 
to  admit  the  driving-pins  B  B,  which  are  made,  as  shown, 
rounded  on  the  ends,  and  driven  tightly  into  the  gear.  The 
driver  8  is  then  made  of  cast-iron  and  bored  to  fit  the  boring- 
bar  or  spindle  0,  as  shown,  being  counterbored  on  the  face  to 
a  depth  and  diameter  sufficient  to  clear  the  jam -nuts  J"  and  the 
sleeve  3.  A  key  is  then  let  into  8  at  (8),  which  fits  freely  the 
keyway  Tin  the  spindle.  The  two  holes  (6)  (6)  coincide  with 
the  pins  B  B  in  the  gear  Q.  The  pinion  (11)  and  shaft  or  stud 
(12)  are  finished  in  one  piece,  the  stud  fitting  the  smaller  hole 
in  E  and  the  pinion  resting  against  the  counterbored  back  of  the 
large  one.  The  stud  is  threaded  at  one  end  for  the  adjusting- 
nuts  shown  at  J  J  in  the  other  three  views. 

All  parts  of  the  head  being  complete,  they  are  assembled  as 
shown  in  Fig.  247,  which  allows  of  the  spindle  being  inserted 
and  withdrawn  freely.  After  the  clamping-levers  L  L,  Figs. 
244,  245,  and  246,  and  the  angular  clamps  J  J  are  finished  and 


INTERCHANGEABLE  MANUFACTURING.         219 

fastened,  all  the  parts  are  assembled  as  shown  in  the  plan  view, 
Fig.  244,  and  the  slots  for  the  cutters  F  F  let  into  the  bar  or 
spindle  0  in  the  position  shown,  at  right  angles  to  each  other. 
The  rig  is  now  ready  for  work. 

The  column,  with  the  bracket  and  heads  in  position,  is  laid 
flat  on  its  back  on  the  bench,  and  the  boring  rig  (with  the  spindle 
slipped  out)  placed  on  the  first  column,  and  fastened  at  G,  Fig. 
244,  by  means  of  the  two  clamps  J,  to  the  dovetailed  surface  of 
it.  The  head  of  the  bracket  and  the  spindle-head  to  be  bored 
project  up  through  the  openings  in  the  centre  of  the  body  cast- 
ing or  base  A.  The  boring-bar  or  spindle  O  is  then  entered 
through  the  head  of  the  rig,  and  through  the  cored  holes  in  the 
bracket  ahd  head,  and  allowed  to  project  slightly  through  the 
tail  C.  The  set ,- screws  M  at  each  side  of  the  bracket-head  and 
spindle-head  are  then  screwed  up,  and  adjusted  to  hold  the  heads 
perfectly  rigid  while  they  are  being  bored.  The  cutters  F  F 
are  then  entered  and  fastened  within  the  bar,  as  shown,  and  the 
driving  belt  shifted  from. the  loose  to  the  tight  pulley.  The  driver 
8  is  then  slid  up,  until  the  two  pins  R  R  in  the  gear  Q  have  en- 
tered the  hole  in  it.  The  spindle  or  boring-bar  is  then  revolving 
at  the  proper  rate  of  speed,  and  is  fed  in  by  grasping  the  handle 
through  the  part  H,  the  pinion  of  which  engages  the  rack,  on 
the  sleeve  of  the  spindle.  The  spindle  is  fed  in  until  the  holes 
are  bored,  when  it  is  fed  back,  and  the  driver  8  pulled  out  and 
the  cutters  removed,  and  another  set  for  finishing  inserted  instead, 
when  the  operation  is  repeated.  When  the  bracket  and  spindle- 
head  of  the  first  column  are  finished,  the  rig  is  removed  and 
clamped  to  the  next  one,  when  the  operation  of  boring  and  finish- 
ing is  repeated,  and  so  on,  until  all  four  heads  and  brackets  have 
been  bored  and  finished  to  size. 

As  can  be  seen,  the  design  and  construction  of  this  boring  rig 
allows  of  its  use  in  the  boring  and  finishing  of  the  heads  and 
brackets  of  all  sensitive  drills  of  from  one  to  six  or  more  spin- 
dles ;  when  the  same  design  and  construction  is  maintained  in 
each.  It  also  allows  of  being  operated  by  comparatively  un- 
skilled help,  without  the  possibility  of  spoiling  the  parts  ma- 
chined by  it.  Its  construction  is  simple  enough  to  satisfy  the 
most  exacting ;  while  the  fact  that  it  is  located  while  in  opera-* 


220 


TOOL-MAKING  AND 


tion  directly  on  the  columns,  adds  to  the  positiveness  and  accu- 
racy of  the  work  produced ;  as  it  does  also  allow  of  the  inter- 
changing of  the  parts  machined. 


BORING   DRILL-PRESS   TABLES. 

On  the  one-spindle  drills,  instead  of  the  sliding  table  used  on 
the  others,  a  flat  swinging  table  and  a  small  round  one  are  sub- 
stituted. The  flat  table  shown  at  A,  Eig.  248,  after  being 
planed  on  all  sides  is  required  to  be  bored  at  F  to  fit  the  turned 
part  on  the  top  of  the  column  on  which  it  swings.  For  finishing 
this  hole — which  was  cored — a  fixture  for  use  in  the  drill-press 
was  designed,  and  also  a  cutter-holder.  The  fixture,  as  shown  in 
Fig.  249,  consists  of  a  flat  casting  with  two  raised  surfaces  at 
B  B  on  which  the  table  rests,  and  the  four  lugs,  C  C  and  D  J> 


Fig.  248. 

for  the  locating-points.  This  casting,  after  being  machined  on 
the  back,  is  finished  on  the  face  by  first  planing  the  raised  sur- 
faces B  B,  and  then  taking  a  cut  down  the  front  of  the  lugs 
C  C  aud  D  D  so  as  to  get  them  at  right  angles  to  each  other 
The  centre  for  the  hole  for  the  bushing  E  is  then  laid  out  and 
located  so  as  to  be  central  with  the  table  sidewise  and  the  proper 
distance  from  the  end  of  the  other.  The  hole  is  then  bored  and 
reamed  to  size  required.  The  bushing  E  is  then  made  and 
hardened,  and  lapped  and  ground  to  size  required ;  then  forced 
tightly  into  the  hole  as  shown.  Holes  are  then  drilled  and  coun- 
terbored  at  the  back  for  the  clamping-bolts,  G  G.  The  two 
straps  are  of  machine  steel  and  are  bent  at  right  angles  at  one 
end,  as  shown.  The  straps  are  finished  to  a  height  sufficient  to 
allowr  of  their  clamping  the  table  securely. 

The  cutters  and  holder  are  shown  in  Fig.  249,  and  as  will  be 
seen  it  is  a  plain  holder  with  two  rows  of  cutters  set  within  it. 


INTERCHANGEABLE  MANUFA  CTUBING. 


221 


The  holder  K  is  of  cast-iron  which  is  first  centred,  and  turned 
taper  at  one  end  to  fit  the  drill-press  spindle,  as  shown,  and  at 
the  other  end,  J,  to  fit  the  bushing  E  in  the  fixture.  The  largest 
portion,  K,  is  turned  to  a  diameter  sufficiently  small  to  allow  the 
cutters  to  project  out  T5¥  of  an  inch.  The  holes  for  the  cutters 
were  drilled  by  setting  the  holder  on  centres  in  the  universal 
milling-machine  and  indexing  for  five,  then  the  first  row  of  holes 
L  drilled.  The  second  row  was  then  drilled  in  the  same  man- 
ner, ^  of  an  inch  higher  up  at  M  and  so  that  each  hole  would 
come  between  two  of  the  first  row.  The  cutters  were  made  of 
Stub  steel  f -inch  in  diameter,  and  were  finished  at  one  end  for 
the  cutting-edge,  as  shown.     They  were  then  set  so  that  the  first 


Fig.  249. 


row  L  would  rough  out  the  hole,  and  the  second  row  of  five  cut- 
ters M  finish  it.  They  were  held  tightly  in  position  by  means 
of  set-screws,  as  shown. 

When  in  use  the  fixture  was  strapped  on  the  table  of  the  large 
drill-press,  in  the  position  shown  in  Fig.  249,  by  means  of  a  bolt 
through  each  end,  at  II  The  cutter-holder  was  then  adjusted 
so  that  the  stem  J  of  holder  would  be  in  line  with  and  enter 
freely  the  bushing  E.  The  table  to  be  bored  was  theii  strapped 
in  position  on  the  fixture  A,  locating  it  squarely  against  the  lugs 
G  C  and  I)  D,  as  shown.  The  stem  J  of  the  cutter-holder  was 
then  entered  into  the  bushing;  E  and  the  feed  thrown  in  and  the 


222  TOOL-MAKING   AND 

hole  bored  and  finished  to  size.  This  is  the  best  way  of  finish- 
ing large  holes  in  flat  surfaces  of  the  kind  shown ;  the  fixture 
beiug  both  reliable  and  simple  in  construction,  as  well  as  rapid 
in  operation.  The  cutters  in  the  holder  K  should  be  left  as  hard 
as  possible,  without  danger  of  cracking,  so  as  to  allow  of  finish- 
ing the  maximum  number  of  holes  without  the  necessity  of  fre- 
quent removal  and  grinding. 

MACHINING   BOUND   TABLES. 

In  Fig.  250  is  shown  two  views  of  the  round  table  as  used  for 
the  small  presses.  This  table  is  in  two  parts — N,  the  table  proper 
of  cast-iron,  aud  0,  the  stem  of  cold-rolled  mild  steel.  The  man- 
ner of  finishing  the  tables  is  as  follows :  The  casting  is  first 
chucked  in  the  turret-lathe  and  the  hole  bored  and  reamed  for 
the  stem;  reaming  it  about  0.003  less  than  the  diameter  of  the 
stem  O.  The  stems  are  simply  cut  off  from  the  bar  in  the  screw  - 
machine,  and  slightly  chamfered  at  each  end.     The  tables  are 

then  heated  in  a  gas- muffler  to  a  dark  red, 

//  \\  when  the  stems  are  inserted  so  as  to  project 

/ '      ('r>Y°    ylm     slightly  above  the  face.     This  way  of  fastening 
ij\         the  stems  is  the  best,  as  it  is  both  rapid  and 
^y   J         permanent.     After  the  tables  have  cooled  suf- 
ficiently to  allow  of  being  handled,  they  are 
liiHililllllliliL— n     face(l  au(l  the  rim  turned  by  holding  them  by 
the  stems  O  in  the  universal  chuck  in  the  lathe. 
[^q  They  are  then  transferred  to  the  grinder,  where 

the  face  is  ground.     This  gives  it  a  neat  and 
mechanical  appearance,  as  well  as  finishes  the 

rii*.  250. 

face  perfectly  flat. 
The  finishing  of  flat  surfaces  by  grinding,  as  in  the  above 
case,  is  far  preferable  and  more  expedient  than  the  one  usually 
employed — that  is,  taking  finishing  cuts  in  the  lathe,  which  is 
an  obsolete  way  of  doing  it  and  very  slow,  especially  when  a  per- 
fectly flat  surface  is  required  on  the  finished  work. 

FINISHING   CUB   CENTRES. 

In  finishing  the  cup  centres  shown  in  Fig.  251  they  are  first 
turned  on  the  stem  P  to  the  same  diameter  as  the  table  stems. 


INTERCHANGEABLE  MANVFA  GT URING. 


223 


They  are  then  fastened  by  the  stems  in  a  nose-chuck  in  the  lathe 
and  the  inside  turned  to  a  sixty  degree  angle  by  using  the  com- 
pound rest,  and  a  special  holder  in  which  self -hardening  steel- 
cutter  is  fastened. 

ADVANTAGES   IN  THE   USE  OF   SPECIAL  TOOLS. 


In  this  chapter,  and  those  precediug  it,  the  number  and 
variety  of  tools  and  fixtures  which  have  been  shown  and  de- 
scribed for  the  duplication  of  parts  have  been  suffi- 
cient to  fully  demonstrate  the  advantages  to  be  gained 
in  manufacturing  by  the  use  of  special  tools  as  com- 
pared with  the  old  methods.  Also,  it  may  be  well 
to  mention  that  the  use  of  such  tools  eliminates  the 
necessity  of  the  results  attained  in  the  work  de- 
pending on  the  skill  and  intelligence  of  the  work- 
men, and  allows  of  employing  less  expensive  help 
in  the  manufacturing  of  various  parts.  While  the 
tools  shown  in  this  chapter  are  the  simplest  and  least  expen- 
sive of  their  class,  if  by  the  study  of  them  they  will  be 
the  means  of  converting  some  of  athe-old-way-is-good-enough- 
for-me  "  sort  of  shops,  to  the  adoption  of  the  system  of  inter- 
changeable manufacturing,  they  will  have  more  than  served  their 
purpose. 


Fig.  251. 


CHAPTER  XV. 

Design,  Manufacture,  and  Use  of  Milling-Cutters. 
MILLING-C  [JTTEKS   CLASSIFIED. 

It  goes  without  saying  that  the  king  of  all  modern  cutting- 
tools  is  the  milling- cutter;  for  that  reason  it  cannot  be  too  fine  a 
piece  of  workmanship.  Of  what  use  would  be  the  plain  or  uni- 
versal milling-machine  without  it?  In  fact,  when  considering 
milling-cutters  it  is  well  to  remember  that  the  milling-machine 
was  created  for  it  and  that  all  the  genius  and  excellent  workman- 
ship put  into  these  wonderful  machines  are  for  no  other  pur- 
pose than  to  rigidly  hold  and  revolve  the  cutter  or  cutters  at  the 
proper  speed,  and  to  feed  the  work  to  it  at  a  rate  suited  to  the 
material  being  milled  and  the  type  of  cutter  doing  the  work. 

Milling-cutters  may  be  classified  in  four  distinct  types.  The 
first  and  probably  the  most  common  form  is  known  as  the  axial, 


Fig.  252. 


FIG.  253. 


Fig.  252,  in  which  the  surface  cut  is  parallel  to  the  axis  of  the 
cutter.  This  cutter  has  teeth  on  its  periphery  only ;  these  may 
be  straight  or  spiral  teeth.  Cutters  of  this  character,  made  in 
appropriate  widths,  are  used  very  much  for  milliDg  broad,  fiat 
surfaces  and  for  cutting  key  ways  in  shafts.  For  deep  cuts,  or 
for  slitting  metal,  they  are  made  of  large  diameter  and  thin. 
These  are  called  metal -slitting  saws,  and  are  ground  hollow  on 

the  sides  for  clearance. 

224 


INTERCHANGEABLE  MANUFACTURING. 


225 


The  second  class  of  cutters  is  known  as  the  radial,  Fig.  253, 
in  which  the  surface  cut  is  perpendicular  to  the  axis  of  the  cut- 
ter. These  cutters  are  called  radial  because  their  teeth  are  used 
in  a  plane  parallel  to  the  radius  of  the  cutter.  End-mills,  face- 
mills,  butt-cutters,  etc.,  are  all  tools  in  this  class. 

The  third  class  of  cutters  is  the  angular,  Figs.  254  and  255, 
in  which  the  surface  cut  is  neither  parallel  nor  perpendicular  to 


FIG.  255. 


WORK/%%? 

w///wW//mW/W//. 

Fig,  256. 


the  axis  of  the  cutter,  but  is  at  some  angle  with  this  axis.  Fre- 
quently cutters  are  made  with  two  different  angular  cutting  edges, 
in  which  case  the  angle  is  marked  on  each  side,  as  in  Fig.  255. 

The  fourth  class  of  cutters  is  the  formed  cutter,  as  shown  in 
Fig.  256.  The  cutting-edge  of  this  class  is  of  an  irregular  out- 
line. When  properly  backed  off,  these  cutters  can  be  ground 
and  retain  their  original  form.  Gear-cutters,  tools  for  grooving 
taps,  etc.,  are  all  classed  as  form  cutters. 

Among  the  numerous  engravings  in  this  chapter  will  be 
found  illustrations  of  a  large  number  of  cutters  which  are  used 
in  milling-machines.  In  most  cases  it  is  advisable  to  use  a  cut- 
ter of  small  diameter  rather  than  of  large  diameter.  Cutters 
from  \\  to  2  inches  in  diameter  are  the  most  economical  for  gen- 
eral milling. 

THE  DESIGN  AND   MANITFACTUBE    OF   MILLING  - 
CUTTEES. 

It  is  conceded  to-day  that  one  of  the  chief  factors  in  bring- 
ing the  process  of  milling  into  universal  use  and  to  the  front 
15 


226  TOOL-MAKING   AND 

rank  of  machine  operations,  was  the  introduction  of  the  emery 
wheel  for  grinding  milling-cutters. 

So  much  attention  has  now  been  given  to  the  milling  process, 
that  in  many  cases  a  degree  of  perfection  has  been  attained  which 
apparently  leaves  little  room  for  improvement.  It  is  still  true, 
however,  that  even  in  up-to-date  shops  the  output  is  below  what 
it  might  be.  Some  firms  undoubtedly  have  developed  milling 
far  beyond  the  rest  of  the  country,  but  as  a  whole  there  is  no 
reason  why  milling  should  not  continue  to  advance  during  the 
present  decade  as  much  as  it  did  in  the  past  one.  It  should 
advance  not  only  in  becoming  more  general  and  more  widely 
applied  but  also  in  the  direction  of  giving  better  results. 

STANDARD   STYLES   AND   SIZES   OF   CUTTER. 

It  is  now  quite  a  common  practice  to  use  cutters  which  are 
not  adapted  to  their  work.  The  number  of  standard  styles  and 
sizes  of  cutters  is  already  enormous,  and  neither  the  manufac- 
turer nor  the  user  can  contemplate  with  equanimity  the  idea  of 
a  large  increase,  and  yet  the  existing  standards  are  inadequate 
for  the  great  variety  of  work  they  have  to  perform.  The  ordi- 
nary standard  cutter  is  intended  to  be  used  on  cast-  or  wrougbt- 
iron,  steel,  or  brass,  and  the  recognized  form  has  been  evolved 
as  the  best  compromise  for  varied  work. 

There  are  many  special  operations  where  the  cutter  passes, 
through  different  metals  at  the  same  time,  or  through  mica,  or 
raw-hide  or  paper,  or  where  any  curious  conditions  arise ;  and 
the  best  form  of  cutter  can  only  be  arrived  at  by  experiment  on 
that  particular  operation.  For  an  individual  job  it  matters  little 
that  a  cutter  is  not  the  very  best  design,  but  with  repetition  work 
it  is  serious  to  use  a  tool  which  is  not  capable  of  giving  the  best 
results. 

UNDERCUT   TEETH. 

A  turning  or  planing  tool  for  iron  or  steel  has  top  rake,  as 
well  as  clearance  below,  and  milling -cutters  for  many  operations 
should  have  similar  rake.  From  experiments,  and  from  general 
experience,  it  has  been  demonstrated  that  undercut  teeth  may 


INTERCHANGEABLE  MANTJFA  GTUBING. 


227 


often  be  used  with  advantage  under  the  following  conditions: 
The  machine  should  be  powerful,  and  the  cutter-arbor  of  ample 
size.  The  pitch  of  the  teeth  should  be  so  coarse  that  only  two 
or  three  may  cut  at  the  same  time.  The  speed  of  cutting  should 
be  slow,  and  the  feed  sufficiently  quick  to  allow  each  tooth  to 
take  a  real  cut.  When  these  con- 
ditions cannot  be  fulfilled,  there 
will  probably  be  no  advantage  in 
departing  from  the  usual  form  of 
tooth. 

Slotting-  or  grooving-cutters, 
spiral  cutters,  and  side-mills  are 
well  adapted  for  undercut  teeth. 
Formed  cutters  may  be  so  made, 
but  there  is  a  difficulty  with  the 
form.  Thus,  in  Fig.  257  if  the  true  form  required  is  made  along 
the  cutting  face  A  B,  the  cutter  will  leave  a  false  form  to  the  line 
A  C.  The  difference  is  in  most  cases  very  slight,  and  always  may 
be  allowed  for  in  making  the  cutter,  but  variations  in  grinding 
the  face  will  alter  the  form.  It  is  easy  in  grinding  them  to  see 
when  the  faces  are  radial,  but  it  is  not  so  simple  to  give  a  known 
amount  of  rake. 

END-MILLS. 


Fig.  257. 


The  question  of  undercut  teeth  also  arises  in  the  case  of  end- 
mills.  Three  methods  of  cutting  the  teeth  are  shown  in  Figs. 
258,  259,  and  260.     Fig.  258  shows  an  ordinary  spiral  end-mill 


FIG.  258. 


Fig.  259. 


with  right-hand  teeth  and  left-hand  spiral,  by  which  arrangement 
the  pressure  from  the  work  always  tends  to  push  the  cutter  into 
its  socket.  This  is  the  correct  form  if  the  cutter  is  to  be  used 
for  milling  on  the  sides,  if,  strictly  speaking,  it  is  not  to  be 
used  as  an  end-mill,  for  which  it  is  unsuitable,  because  the 
teeth  on  the  end  have  negative  clearance  and  would  not  cut 


228  TOOL-MAKING  AND 

freely.  For  end-cutting,  the  ordinary  straight  teeth  shown  in 
Fig.  259  are  more  suitable,  and  in  some  cases  a  right-hand  cutter 
with  a  left-hand  spiral  would  be  best  of  all  (see  Fig.  260).    This 


Fig.  260. 

gives  correct  clearance  to  the  end  teeth,  and  when  used  under 
favorable  conditions  such  a  cutter  has  no  more  tendency  to  leave 
its  socket  than  a  twist-drill,  which  is  made  on  exactly  the  same 
principle. 

SIDE   CLEARANCE. 

Standard  cutters  frequently  give  trouble  in  the  matter  of  side 
clearance.  It  is  assumed  that  the  cutter  must  not  lose  its  width 
on  resharpening,  but  there  must  be  some  dishing  on  the  sides,  or 
it  would  be  unworkable ;  accordingly  a  very  slight  clearance  is 
given,  say  one-half  degree  each  side,  which  will  cause  the  cutter 
to  become  two-thousandths  (0.002)  thinner  when  ^-inchhas  been 
ground  away  in  diameter.  The  cutter  would  be  more  service- 
able if  it  had,  say,  one  degree  clearance  each  side,  but  that  would 
cause  it  to  lose  its  width  too  soon.  Now  suppose  a  quantity  of 
work  is  required  where  the  width  of  groove  is  not  particular  to 
one-fiftieth  (0.02)  of  an  inch,  or  where  the  cutter  is  only  used  for 
roughing,  it  would  be  worth  while  to  take  a  standard  cutter  and 
grind  extra  clearance  on  it.  This  is  particularly  the  case  when 
cutting  brass,  which  is  very  liable  to  bind  on  the  sides. 

INSERTED   TOOTH-CUTTEES. 

The  time  has  now  arrived  when  a  great  development  should 
take  place  in  the  direction  of  cutters  with  inserted  teeth.  The 
obvious  advantages  are : 

1.  That  cheap  material  may  be  used  for  the  body  of  the  cut- 
ter, and  the  very  best  high-speed  cutting-steel  for  the  blades. 

2.  Hardening  difficulties  are  reduced  to  a  minimum. 

3.  When  worn  out  the  blades  may  be  replaced  at  a  small  ex- 
pense. 


INTERCHANGEABLE  MANUFA  CTUEING. 


229 


The  great  objection  is  the  first  cost,  particularly  in  the  case 
of  cutters  less  than  about  seven-inch  diameter.  Also  inserted 
blades  are  usually  not  very  suitable  for  wide  cuts.  The  supe- 
riority of  the  inserted  tooth-cutter  is  most  unquestionable  in  the 
case  of  side-  or  straddle-mills  which  are  mainly  cutting  on  the 
corners. 

One  widely  used  method  of  holding  the  blades  is  shown  in 
Fig.  261.  "the  blade  A  is  ground  on  the  sides.  The  bush  B  is 
turned  parallel  and  has  a  flat  milled  on  it  at  an  angle  with  the 

X 


SECTION  X-Y 


FIG.  361. 

centre  line.  This  bush,  which  fits  in  a  recess,  as  shown,  is  sim- 
ply a  wedge  and  is  knocked  in.  There  is  a  screw  G  to  prevent 
it  coming  loose.  A  second  screw  D,  a  patent  one,  is  shown  for 
adjusting  the  blades  side  wise.  There  seems  to  be  no  reason  why 
these  cutters  should  not  largely  displace  solid  side-mills  except 
in  the  smaller  sizes. 


LIMITS   OF   INACCURACY. 

Coming  now  to  the  manufacture  in  quantities  of  cutters,  the 
great  principle  of  "good  enough  "  asserts  itself.  It  must  first  be 
determined  exactly  what  "good  enough"  is,  and  the  drawing 
must  show  that  exactly.  Any  time  spent  in  making  a  measure- 
ment nearer  to  a  dead  size  than  is  called  for  is  a  loss.  Fig.  262 
is  a  working  drawing  of  a  simple  cutter  which  is  to  be  measured 
with  the  micrometer,  and  not  with  limit-gauges. 

According  to  this  drawing,  it  has  been  determined  that  if 
error  in  the  thickness  of  a  |-inch  cutter  does  not  exceed  one- 
thousandth  (0.001)  of  an  inch,  it  is  good  enough.  This  is  clearly 
shown,  and  the  grinder  must  adhere  to  the  limits  given,  but  must 


230 


TOOL-MAKING  AND 


not  waste  time  in  making  every  ^-inch  cutter  to  within  one-half 
thousandth  (0.0005)  of  the  nominal  size. 

Again,  it  has  been  found  that  about  one-hundredth  (0.01)  is 
a  reasonable  allowance  for  cleaning  out  the  turning  marks  on 

the  sides  after  hardening.     It  is,  how- 

TFETH  24 

ever,  quicker  to  grind  off  a  few  extra 
thousandths  than  to  turn  them  off, 
and  the  lathesman  must  keep  within 
the  limits — ten  to  fifteen  thousandths 
above  -|-inch.  £:J4|.  He  has  no  ex- 
cuse for  leaving  too  much  or  too  lit- 
tle for  grinding,  nor  yet  for  wasting 
time  by  taking  a  cut  of  two  thou- 
sandths (0.002)  off  the  side. 

It  is  shown  that  the  actual  diam- 
eter is  not  important,  and  the  lathes- 
man  has  a  limit  of  one-hundredth 
(0.01)  of  an  inch,  which  means  that 
the  grinder  must  just  clean  out  the 
turning  marks. 

The  drawing  shows  that  the  side 
recesses  may  vary  in  diameter  by  one-tenth  (0.1)  of  an  inch. 
The  clearance  each  side  is  stated  as  one-half  degree,  and  it  is 
essential  that  this  shall  run  out  to  the  extreme  tips  of  the  teeth. 


USE   AND   ABUSE   OF   CUTTEES. 

A  whole  chapter  might  well  be  devoted  to  the  use,  abuse,  and 
maintenance  of  milling  cutters.  A  slignt  reference  only  can 
be  made  to  this  branch  in  a  chapter  dealing  mainly  with  their 
design  and  manufacture. 

It  is  a  source  of  great  satisfaction  to  the  maker  that  when  a 
cutter  is  broken  by  being  run  backwards  on  to  the  work,  the 
breakage  is  characteristic.  A  cutter  may  be  taken  that  has  been 
spoilt  in  this  way,  and  although  the  man  who  broke  it  will  be 
absolutely  sure  that  it  ran  in  the  right  direction,  the  cracks 
down  the  faces  of  the  teeth  tell  a  different  story. 

On  many  operations  it  is  of  the  first  importance  to  have  a 
full  flood  of  lubricant ;  a  trickle  is  not  sufficient. 


INTERCHANGEABLE  MANUFACTURING.  231 

EEGEINDING. 

It  cannot  be  too  strongly  insisted  that  it  is  very  wasteful  to 
use  a  dull  cutter.  It  is  as  hopeless  to  mill  successfully  without 
adequate  grinding  arrangements  as  it  would  be  to  turn  satisfac- 
torily with  only  the  door-step  to  sharpen  the  tools  on.  When  a 
cutter  is  changed  in  time,  the  sharpening  should  only  occupy  a 
very  few  minutes  for  most  small  sizes.  If  run  too  long,  the 
grinding  becomes  a  serious  operation,  which  causes  the  grinder 
to  lose  his  temper,  and  to  draw  the  temper  of  the  cutter. 

When  the  resharpening  cannot  be  accomplished  by  two  or 
three  passes  over  the  emery  wheel,  the  cutter  should  be  mounted 
on  a  mandrel  and  ground  whilst  revolving  until  the  worn  part 
has  all  been  removed ;  and  the  tooth-by-tooth  grinding  should 
be  reserved  for  backing  off  to  give  the  cutting  edge.  Not  only 
is  this  much  the  quicker  way,  but  there  is  no  risk  of  drawing  the 
temper  if  ordinary  care  be  exercised. 

It  must  always  be  remembered  that  however  good  a  cutter  is, 
the  cutting-edge  may  be  so  damaged  by  a  little  carelessness  in 
grinding  as  to  receive  any  degree  of  injury  up  to  the  point  of 
being  ruined.  It  is  well  to  touch  the  cutting -edge  with  an  oil- 
stone after  grinding. 

As  the  teeth  are  usually  reground  on  a  dry  wheel,  it  is  impor- 
tant that  arrangement  should  be  made  for  exhausting  the  dust 
produced.  Dry  grinding  is  now  recognized  as  a  dangerous  occu- 
pation, causing  lung  diseases.  The  operation  is  not  capable  of 
imparting  consumption  itself,  but  it  so  irritates  the  throat  and 
lungs  as  to  keep  them  in  an  unhealthy  condition  and  render  them 
susceptible  to  consumption  germs.  For  this  reason  the  emery 
wheel  should  be  enclosed,  as  far  as  possible,  in  a  hood,  and  a 
good  exhaust  provided  by  a  fan  or  other  suitable  means. 

QUALITY   OF   STEEL  TO   USE  FOE  MILLING- 
CUTTEES. 

The  all-important  question  of  the  quality  of  steel  to  be  used 
is  too  often  ignored.  Self-evident  as  it  is,  the  fact  may  yet  be 
overlooked  that  two  cutters,  one  made  of  the  best  steel  and 


232  TOOL-MAKING  AND 

one  of  the  worst,  may  be  identical  in  appearance,  and  the  differ- 
ence will  only  become  apparent  in  use. 

In  small  or  complicated  cutters,  in  which  the  cost  of  steel  is 
only  a  small  proportion  of  the  total  cost,  the  amount  saved  by 
using  cheap  steel  is- slight. 

In  large  cutters  of  simple  forms  with  little  machining  on 
them,  where  the  cost  of  steel  is  perhaps  one-third  or  even  one- 
half  the  cost  of  the  finished  cutter,  the  saving  effected  by  using  a 
poorer  quality  of  steel  amounts  to  a  great  deal,  and  may  recon- 
cile the  user  to  an  inferior  cutting  edge.  Good  steel  may  be  re- 
cut,  and  after  the  hardening  the  cutter  should  not  be  perceptibly 
inferior  to  a  new  one. 

SELECTING   A   SET   OF   CUTTEES   FOE  A  MLLLING- 

MACHINE. 

A  person  buying  a  milling-machine  for  general  use,  who  has 
not  had  previous  experience,  is  immediately  confronted  with  the 
problem  of  cutters,  and  the  questions  are  frequently  asked,  "  What 
should  I  buy  for  a  starter?  "  and  "What  is  likely  to  be  required 
for  my  work  ?  "  It  is  to  this  class  that  these  suggestions  are 
offered  rather  than  to  those  who  by  years  of  experience  and 
study  are  prepared  to  give  counsel  and  are  not  in  need  of  what 
I  have  to  offer. 

To  begin  with,  do  not  under  any  circumstances  buy  up  a  lot 
of  second-hand  cutters  because  they  can  be  had  at  a  bargain,  as 
they  are  liable  to  prove  very  expensive  in  the  end  for  many  rea- 
sons. They  may  be  unsuited  for  the  work,  out  of  date  in  design, 
and  will  unconsciously  be  copied  in  the  new  cutters  that  are 
made,  or  they  may  be  worn  away  so  that  further  grinding  is  im- 
possible and  consequently  useless. 

AN  ASSOETMENT   OF   MILLING-CUTTEES. 

The  assortment  of  cutters  shown  in  Fig.  263  makes  a  good  set 
to  put  with  the  new  milling-machine.  A  wide  range  of  work 
can  be  done  with  them,  including  the  making  of  new  cutters  of 
almost  any  style  or  size.  This  set  consists  of  two  of  No.  6  and 
one  mill  arbor,  suitable  for  shell -end  mills  from  2^  to  5  inches 


INTERCHANGEABLE  MANUFACTURING. 


233 


in  diameter,  and  No.  7  illustrates  an  end-mill  1\  inches  in  diam- 
eter to  fit  it.  The  arbor  has  a  threaded  collar  with  tongues  to  fit 
in  the  slots  milled  in  the  back  end  of  the  cutter  for  driving  it. 

The  screw  tapped  into  front  end  of  the  arbor  drops  into  the 
counterbore  in  the  •  cutter,  thus  keeDing  out  of  the  way  of  the 


chips  and  holding  the  cutter  in  place.  Figs.  264  and  265  show 
two  other  styles  of  end-mills  and  arbors,  each  having  something 
to  recommend  them.  The  cutters  shown  in  the  group  at  the 
right  are  tapped  standard,  and  have  a  slot  milled  across  the 
back  end  to  fit  the  loose  collar,  which  is  used  to  force  off  the  cut- 
ter and  serve  no  other  purpose.  If  desired,  the  cutter  itself 
could  be  extended  and  milled  to  fit  a  wrench,  the  only  objection 
being  that  the  cutter  would  be  slightly  more  expensive. 

The  arbor  shown  with  cutters  to  fit  in  Fig.  264  has  No.  10 
B.  &  S.  taper  to  fit  in  the  machine,  No.  4  Morse  taper  in  front 


Fig.  264. 


FIG.  265. 


to  fit  the  cutters,  and  Woodruff  key  to  do  the  driving.  It  has  a 
nut  to  force  the  cutter  off  and  a  screw  to  hold  it  on,  the  same  as 
the  screw  in  No.  1  of  Fig.  263. 

These  three  styles  of  arbors  and  cutters  are  excellent  and  any 
one  of  them  will  give  good  results.     The  threaded  cutter  is  the 


234  TOOL-MAKING  AND 

cheapest  because  it  does  not  require  internal  grinding  or  lap- 
ping. The  taper-arbor  and  its  cutter  are  perhaps  slightly  more 
expensive  to  make,  because  it  is  necessary  that  the  cutter  be 
ground  internally  to  fit  the  taper.  This  is  to  be  recommended 
when  the  most  accurate  work  is  required. 

SHELL  END-MILLS. 

Shell  end -mills  are  very  useful  cutters  and  will  be  largely 
used  wherever  a  milling-machine  is  supplied  with  them. 

Small  end-mills  should  be  made  solid,  perferably  with  taper- 
shanks  (Nos.  3  and  4,  Fig.  263),  as  the  most  accurate  and  satis- 
factory way  to  hold  them. 

SPINDLE   SURFACE-MILLS. 

The  spindle  surface-mill  (No.  5,  Fig.  263)  is  2^  inches  in 
diameter,  3  inches  face,  and  is  one  of  a  great  variety  listed  by 
the  cutter  manufacturers  whose  practice  is  to  make  with  straight 


Fig.  266. 

teeth  where  the  face  is  less  than  f-inch  wide.  This  style  of  cut- 
ter, in  widths  to  suit,  is  commonly  used  for  key-seating. 

Cutters  with  side  teeth  (No.  6)  could  be  used  for  key-seating, 
but  it  is  obvious  that  they  would  fall  below  size  much  sooner 
than  the  cutter  with  outside  teeth. 

Teeth  milled  spiral  will  do  better  work  on  wide  cuts  than 


INTERCHANGEABLE  MANUFACTURING.         235 

when  milled  straight,  on  account  of  the  shearing  out,  and  for 
heavy  roughing  the  teeth  should  be  nicked  by  cutting  a  coarse 
thread  around  the  blank  before  milling  the  teeth. 

The  side-cutter  is  most  useful  in  pairs  for  milling  both  sides 
of  a  piece  at  once,  like  squaring  a  tap-shank ;  the  cutters  oper- 
ating on  opposite  sides  of  the  piece  take  away  any  tendency  to 
spring  and  produce  accurate  work  rapidly. 

GANG-MILLS   AND   INTEBLOCKING  CUTTEBS. 

A  gang  of  spiral  surface -cutters  with  side  teeth,  the  inner  pair 
made  interlocking,  is  shown  in  Fig.  266.  The  teeth  are  cut 
spiral,  right  and  left  hand  alternately,  to  balance  any  side-thrust 
and  to  give  top  rake  to  the  side  teeth  doing  the  cutting.  The 
inner  pair  are  made  with  clutch  teeth  to  interlock ;  the  bearing- 
faces  being  scooped  out  to  allow  the  clutch  teeth  to  engage. 
Paper  is  used  to  extend  the  cutter  as  the  sides  are  ground  away, 
maintaining  a  constant  size  and  insuring  interchangeability. 
The  same  cutters  can  also  be  used  for  roughing  and  finishing  by 
taking  out  some  of  the  packing  while  roughing,  and  restoring 
the  cutters  to  the  proper  width  before  taking  the  finishing  cut. 

Fig.  266  shows  a  group  of  common  forms.  Care  should  be 
taken  in  grinding  to  have  the  face  of  the  teeth  radial ;  the  ten- 
dency is  to  grind  the  point  more  than  the  base  of  the  tooth,  which 
places  the  cutting-edge  at  a  great  disadvantage. 

Generally  it  is  more  economical  to  buy  standard  cutters  from 
the  maker,  and  in  many  instances  special  ones  also,  but  it  is  at 
times  desirable  to  do  some  of  this  work  at  home,  being  cheaper 
if  the  tool-room  is  properly  equipped  and  organized,  and  the 
educational  advantage  of  such  work  has  a  distinct  value. 

MAKING   CUTTEES. 

For  making  cutters,  Kos.  10,  11,  and  12  of  Fig.  263  provide 
a  good  outfit.  The  first  two  have  sixty  degree  angles,  one  right 
and  one  left  hand,  and  will  suffice  for  most  straight  tooth  work. 
No.  12  is  for  milling  spiral  cutters  and  has  twelve  degree  angles 
on  one  side  and  forty  degree  on  the  other. 

Practice  has  shown  that  it  is  best  to  make  cutters  with  radial 


236  TOOL-MAKING  AND 

teeth.  If  they  are  undercut  so  as  to  give  the  cutting-edge  top- 
rake,  as  in  a  lathe-tool,  it  makes  a  weak  tooth  liable  to  break 
easily,  but  adds  to  the  efficiency  of  heavy  ones. 

There  is  far  more  danger  of  getting  too  many  teeth  than  too 
few  into  a  cutter. 

If  the  cutter  is  small  in  diameter  so  that  it  will  become  too 
thin  if  the  teeth  are  deep,  take  the  first  cat  through  at  the  proper 
depth  and  then  mill  around  again  after  revolving  the  work  so  as 
to  bring  the  proper  angle. 

MOST  VITAL   POINT     IN  MILLING-MACHINE 
PEACTICE. 

The  most  vital  point  in  milling-machine  practice  is  that  cut- 
ters of  whatever  design  be  kept  sharp.  A  dull  cutter  is  like 
any  other  tool  that  is  dull — its  efficiency  is  greatly  reduced,  the 
work  produced  is  inferior,  and  the  cutter  wears  rapidly  away. 

The  same  principle  applies  to  the  cutting-edge  of  the  milling- 
cutter  as  to  any  other  cutting-tool  for  metal.  If  too  little  clear- 
ance is  ground  it  will  not  cut  well,  and  if  too  much,  it  will  chat- 
ter ;  about  three  degrees  will  generally  give  good  results. 

SPEEDS  AND   FEEDS  FOE  MILLING-CUTTEES. 

A  subject  upon  which  too  much  cannot  be  written  nor 
thought  given  is  that  of  proper  speeds  and  feeds  for  milling- 
cutters.  Often  the  question  is  asked:  "What  lule  is  there  for 
determining  the  proper  speeds  of  cutters. "  When  a  direct  an- 
swer is  not  given  to  this  question,  the  questioner  is  always  dis- 
satisfied and  usually  discouraged.  Of  course  there  is  no  "hard 
and  fast "  rule  for  determining  the  proper  feeds  and  speeds  of 
cutters,  and  in  this  book  one  cannot  be  given.  The  texture  and 
hardness  of  the  material  to  be  machined  determines  the  surface 
speed  in  each  case.  Thus,  for  cast-iron,  a  speed  of  forty  feet 
per  minute  may  be  safely  taken  as  a  good  basis  when  taking 
heavy  roughing  cuts,  while  for  light  finishing  cuts  on  the  same 
material,  (after  the  scale  has  been  removed)  fifty  feet  per  minute 
is  not  too  fast.     When  working  steel  twenty  feet  per  minute  is 


INTERCHANGEABLE  MANVFACTURING.         237 

not  too  fast,  and  for  brass  sixty  feet  per  minute  is  a  good  basis 
for  determining  the  correct  cutting  speeds  for  these  metals. 

Although  the  hardness  and  texture  of  the  material  worked 
upon  is  the  chief  factor  to  be  considered  when  determining  mill- 
ing speeds,  the  nature  of  the  cut  and  the  shape  are  also  very  im- 
portant factors.  Thus,  for  instance,  a  large  slitting-saw  can  be 
run  about  twice  as  fast  as  a  large  surface -cutter  when  working 
on  the  same  material. 

JS~ow,  with  regard  to  the  rate  of  feeds  for  milling,  the  most 
advanced  practice  is  to  take  a  roughing-cut  with  the  fastest  feeds 
the  macbine  will  pull ;  that  is,  provided  the  cutter  is  relatively 
as  strong  in  comparison  as  the  machine  in  which  it  is  used.  If 
the  nature  of  the  work  requires  a  cutter  of  such  a  form  as  to  be 
comparatively  weak,  it  is  often  better  economy  to  break  an  occa- 
sional cutter  than  to  allow  the  machine  to  work  at  a  slow  rate  of 
speed. 

When  running  a  cutter  at  a  slow  rate  of  speed  and  advancing 
it  at  a  fast  rate  of  feed  on  cast-iron,  compressed  air,  delivered  to 
the  cutter  with  sufficient  force  to  clear  away  all  chips  as  fast  as 


Fig.  267. 

they  are  produced,  will  j>rolong  the  life  of  the  cutter,  even  when 
the  fastest  feeds  are  fed  against  it.  When  working  steel,  a 
stream  of  oil  on  the  cutter  will  have  the  same  effect,  providing 
the  oil  is  delivered  under  pressure  sufficient  to  wash  away  the 
chips  entirely  from  the  cutter. 

In  regard  to  "  burning  "  cutters,  or  drawing  the  temper  while 
working  them,  it  must  be  understood  that  this  will  not  happen 
through  too  fast  a  feed,  but  it  is  always  to  be  traced  to  too  high 
speeds.  Thus,  when  both  speed  and  feed  are  up  to  the  maxi- 
mum, the  actual  rate  of  table  travel  per  minute  can  be  further 


238  TOOL-MAKING 

increased  by  reducing  the  speed  of  the  cutter  and  increasing  the 
feed  rate. 

When  taking  finishing  cuts,  the  rate  of  speed  depends  upon 
the  quality  and  degree  of  finish  required.  Here  it  may  be 
stated  that  experiments  have  determined  that  0.030  per  revolu- 
tion of  a  3^-inch  cutter  when  surface-milling  leaves  a  good  fin- 
ish, and  in  machine  work  will  leave  a  surface  that  will  require 
little  scraping  to  make  a  good  bearing. 

Fig.  267  shows  a  collection  of  forming  cutters. 

To  succeed  with  milling-cutters  they  should  be  made  right, 
hardened  properly,  sharpened  regularly,  and  speeded  and  fed 
properly. 

SUGGESTIONS   FOR   MILLING. 

Experience  in  the  use  of  milling-cutters  will  teach  anyone 
that  unnecessary  expense  and  annoyance  may  be  avoided  by  fre- 
quent and  proper  grinding  of  milling-cutters.  A  dull  mill  will 
not  do  good  work  and  wears  away  very  rapidly.  At  the  first 
appearance  of  dullness,  use  your  cntter-grinder,  it  will  save 
your  cutters,  your  time,  and  your  patience,  and  will  enable  the 
cutters  to  do  their  best  and  most  rapid  work. 

In  order  to  preserve  the  correct  shape  of  formed  corners, 
grind  the  teeth  radially. 

No  definite  rule  can  be  given  for  speed  or  feed  of  cutters,  but 
the  usual  tendency  in  all  classes  of  Avork,  except  for  finishing 
cuts,  is  for  slow  speeds  and  coarse  feeds. 

For  cutting  wrought-irou  or  steel  use  lard,  oil,  or  some  one  of 
the  usual  compounds  manufactured  for  this  purpose. 

Small  mills  on  horizontal  millers  will  cut  better  and  faster 
than  larger  mills ;  they  also  cost  less  and  will  last  longer. 

Wherever  possible  use  a  mill  that>is  wider  than  the  cut  to  be 
taken. 


CHAPTER  XVI. 

The  Hardening  and  Tempering  of*T\ffilling-Cutters. 
HAEDEOTNG. 

Although  the  quality  of  steel  used  for  milling-cutters  is  of 
great  importance  the  proper  hardening  of  it  is  eepially  so.  It  is 
a  fact  that  bad  steel  well  treated  will  make  better  cutters  than 
good  steel  poorly  treated.  The  hardeners  of  such  tools  cannot 
complain  of  a  lack  of  literature,  as  treatises  and  articles  on  the 
subject  are  continually  appearing.  However,  practice  alone  can 
teach  the  details  and  refinements  of  the  most  interesting  process 
in  the  making  of  milling-cutters. 

In  the  following,  methods  are  put  forward  for  the  proper 
hardening  of  milling  cutters  which  are  the  result  of  experience, 
and  while  they  are  not  necessarily  the  best,  it  is  claimed  that 
they  have  brought  success  when  used. 

It  pays  to  spend  time  on  filling  blind  holes,  sharp  internal 
angles,  etc.,  with  clay.  In  many  cases  asbestos  should  be  used 
with  wire  over  a  weak  place,  or  over  a  part  which  must  be  kept 
soft.  The  furnaces  should  be  in  a  partially  darkened  room 
from  which  direct  sunshine  is  excluded. 

Though  I  have  never  found  any  disadvantage  in  using  cold 
water  for  quenching,  it  is  quite  reasonable  to  suppose  that  water 
containing  a  considerable  amount  of  air  dissolved  in  it  may  not 
cool  the  cutter  so  uniformly  as  it  would  do  if  the  air  had  been 
expelled,  and  therefore  boiled  water  is  to  be  preferred. 

After  machining,  tools  should  have  a  few  days  rest  before 
hardening.  If  they  must  be  hardened  immediately,  they  should 
be  annealed  first,  but  care  must  be  taken  to  prevent  a  tendency 
for  the  surface  to  become  decarbonized.  To  accomplish  this,  an 
excess  of  charcoal  should  be  kept  near  the  cutters  in  the  furnace 
to  maintain  a  reducing  atmosphere. 

239 


240  TOOL-MAKING   AND 


HEATING. 


It  is  not  only  necessary  that  the  cutter  should  be  at  the  right 
heat,  and  at  a  uniform  heat,  when  plunged,  hut  it  must  have 
reached  that  heat  gradually  and  uniformly.  If  the  heat  be  applied 
gradually,  the  cutter  may  be  made  hotter  than  the  correct  tem- 
perature, and  yet  not  crack.  If  a  crack  appear  under  these  cir- 
cumstances, it  will  probably  go  through  the  cutter.  If  a  cutter, 
after  being  heated  too  rapidly,  or  allowed  to  get  much  too  hot, 
be  carefully  brought  to  the  right  temperature  in  the  furnace  and 
then  plunged,  the  teeth  may  clink  off.  They  are  certain  to  do 
so  if  it  be  not  nearly  uniform  in  temperature  at  the  time  of 
plunging.  In  case  of  a  mistake  in  heating,  a  cutter  should  be 
allowed  to  cool  out,  and  heated  fresh. 

PLUNGING. 

The  manner  of  plunging  is  worth  attention.  A  thin  cutter 
should  be  in  a  vertical  plane  when  it  enters  the  water.  If  it 
were  plunged  horizontally,  one  side  would  be  cooled  before  the 
other,  and  would  cause  the  cutter  to  warp.  A  cutter  with  a  long 
hole  should  be  plunged  into  the  bath  with  the  hole  vertical,  to 
allow  the  water  to  circulate  freely.  Cutters  with  large  recesses 
should  be  plunged  with  the  recess  uppermost — to  allow  the  steam 
to  escape.  The  object  generally  is,  in  the  first  place,  to  cool 
symmetrical  parts  simultaneously ;  and,  secondly,  to  let  the  water 
have  free  access  to  every  part  without  delay.  Thus  a  long  thin 
reamer  should  obviously  be  dipped  endwise,  in  order  that  all 
the  flutes  may  cool  simultaneously,  notwithstanding  the  fact 
that  the  water  would  come  into  contact  with  every  part  in  a 
shorter  time  if  it  were  dipped  horizontally. 

Cutters  need  not  be  cooled  right  out  in  the  water.  They  may 
be  removed  as  soon  as  they  are  so  far  chilled  that  the  temper 
color  would  barely  show  if  they  were  polished  immediately. 
Cutters  of  a  few  pounds  weight  may  be  lifted  from  the  water  as 
soon  as  the  teeth  are  chilled.  In  a  few  minutes  the  heat  from 
the  inside  begins  to  reheat  the  teeth,  and  just  before  the  color 
shows  they  must  be  plunged  again  for  a  second  or  two.     This 


INTERCHANGEABLE  MANUFACTURING.         241 

may  be  repeated  three  or  four  times  or  more,  according  to  the 
size  of  the  cutters.  When  at  last  they  are  cool  enough,  they 
should  be  maintained  for  a  few  minutes  at  a  heat  sufficient  to 
just  show  color — a  light  straw — and  then  allowed  to  cool  out  in 
the  air.  In  order  to  see  the  color,  it  will  be  necessary  to  have 
another  piece  with  a  clean  surface  for  comparison. 

WARPING. 

Change  in  shape  in  hardening  may  be  largely  prevented  by 
previous  annealing,  by  keeping  to  the  very  lowest  temperature 
that  will  give  sufficient  hardness,  and  by  the  utmost  uniformity 
of  heat  in  every  part. 

LEAD   BATH. 

Long  thin  reamers  may  be  uniformly  heated  in  red-hot  lead. 
It  is,  however,  important,  in  order  to  prevent  the  lead  from 
being  cooled  by  the  immersion  of  cold  articles,  and  also  to  avoid 
injury  to  the  articles  themselves  by  too  sudden  heating,  that 
reamers  or  other  articles  should  be  independently  heated  to  a 
red  just  below  the  hardening  temperature,  and  the  lead  bath 
should  be  reserved  for  the  final  heating,  the  lead  should  be  that 
sold  as  "chemically  pure, "  and  when  in  use  there  should  be  a 
great  abundance  of  small  charcoal  floating  on  the  surface  to  pre- 
vent the  formation  of  dross  which  would  cling  to  the  teeth. 

DEGREE  OF   HARDNESS. 

Whether  heated  in  lead  or  not,  the  teeth  of  a  finished  cutter 
should  be  as  hard  as  a  good,  new,  smooth  file.  They  should 
scratch  glass. 

INJURY  IN  HARDENING. 

It  has  been  stated  above  that  steel  may  be  overheated,  and 
yet  not  crack  if  the  heat  be  very  uniform.  This  point  must  be 
strongly  insisted  upon,  and  claims  careful  attention.  It  means 
that  we  must  not  regard  breakage  as  a  dividing  point  between 
good  and  bad  hardening.  It  is  the  division  between  bad  and 
worse.     When  steel  is  badly  treated,  it  will  lose  its  best  propor- 


242  TOOL-MAKING   AND 

tion  long  before  the  treatment  is  so  very  bad  as  to  cause  actual 
rupture.  If  in  a  large  hardening  a  considerable  quantity  of  tools 
are  broken,  it  is  probable  that  many  of  the  remainder  are  as  bad 
as  they  can  be  without  actually  breaking ;  but  if  none  are  broken 
it  is  reasonable  to  assume  that  many  are  well  hardened.  A  good 
hardener  need  not  be  afraid  of  occasionally  getting  a  cutter 
barely  hard  enough  or  just  doubtful  in  hardness,  because  a  heat 
which  accomplishes  this  will  do  the  steel  no  harm,  and  it  may  be 
rehardened;  meanwhile  the  operator  has  the  satisfaction  of 
knowing  that  the  remainder  of  the  day's  work  is  probably  very 
accurate  indeed. 

There  are  then  two  extremes  which  are  unquestionable.  A 
cutter  which  on  the  one  hand  is  not  hard  enough,  or  on  the  other 
hand  is  broken,  evidently  cannot  be  passed. 

TEST   OF   HABDENLNG. 

As  steel  may  be  between  these  obvious  limits  and  yet  be 
damaged,  a  finer  test  is  demanded,  for  if  the  hardener  is  to  hit 
the  exact  point  he  must  know  exactly  what  success  he  has. 

SAND-BLASTING. 

For  this  purpose  the  following  method  has  frequently  been 
adopted  with  success.  After  being  hardened  and  tempered  in 
the  usual  manner,  the  cutters  are  dipped  in  oil  and  then  sand- 
blasted. If  there  has  been  any  overheating  in  the  furnace, 
though  not  enough  to  do  any  apparent  harm,  cracks  will  appear 
on  the  faces  of  the  teeth.  These  cracks,  which  are  best  seen  im- 
mediately after  sand-blasting,  are  frequently  so  small  that  they 
cannot  be  detected  by  ordinary  means,  and  if  the  teeth  are 
broken  off  the  breakage  will  probably  not  follow  them.  A  cut- 
ter on  which  the  sand-blast  reveals  numerous  cracks  may  still  be 
quite  passable — indeed,  it  would  have  been  considered  perfect 
but  for  this  test.  Here  is  a  means  of  trying  the  work  of  the 
hardener  between  narrower  limits,  and  he  has  a  warning  that  he 
is  giving  too  much  fire  before  a  tool  is  spoilt. 

The  sand-blasted  cutter  also  possesses  another  advantage  of 
some  importance  in  the  fact  that  if  the  temper  be  drawn  in 


INTERCHANGEABLE  MANUFACTURING.         243 

grinding  sufficiently  to  cause  any  discoloration,  the  tell-tale  line 
will  show  distinctly  on  the  face  of  the  tooth,  and  cannot  be  re- 
moved by  another  pass  along  the  wheel. 

HEATING  AND   HAEDENING  LAEGE  CUTTEES. 

The  following  method  of  getting  a  good  uniform  test  on  a 
large  cutter,  say  about  9  inches  diameter  and  2£  inches  thick,  in 
an  ordinary  blacksmith  fire  is  over  good,  and  if  followed  out 
carefully  will  result  in  perfect  satisfaction. 

After  getting  a  good  deep  fire,  with  plenty  of  well-coked 
blacksmith's  coal  as  a  foundation,  and  having  the  sides  of  the 
fire  well  banked  up  with  fresh  coal,  the  cutter  should  be  placed 
in  the  fire  and  covered  over  with  "live"  coals  of  coke  and  the 
whole  brought  up  slowly  until  the  cutter  begins  to  show  some 
red. 

Then  place  some  dry  pine  boards,  about  one  inch  thick,  over 
the  top  of  the  fire  and  almost  entirely  shut  the  blast  off.  The 
boards  of  course  will  take  fire  and  soon  become  live  coals.  The 
cutter  should  then  be  turned  over  and  a  second  layer  of  boards 
placed  over  the  fire. 

By  the  time  these  are  burned  to  good  live  coals  we  will  have 
a  thorough,  uniform  heat.  Then  after  a  slight  application  of 
the  blast,  so  as  to  be  sure  to  quench  on  a  rising  heat,  and  two  or 
three  turnings  of  the  cutter  in  the  fire,  in  order  to  keep  the  heat 
uniform,  the  cutter  will  be  ready  to  quench. 

This  may  be  done  in  "brine,"  allowing  the  tool  to  remain  in 
the  bath  about  fifty  seconds.  Then  quickly  withdraw  it  and 
place  it  in  a  tank  of  oil  to  finish  cooling.  The  heating  should 
take  about  thirty-five  minutes. 

Although  a  good  gas  furnace  should  be  used  for  such  a  job 
as  the  above,  I  realize  that  this  is  not  always  to  be  had  when 
wanted. 

Finally,  of  hardening,  it  may  be  said  that  it  is  the  most  diffi- 
cult and  the  most  interesting  part  of  cutter-making. 


CHAPTER  XVII. 

Drills    and    Drilling,   Forming-Tools,   Facing-Tools, 
Counterbores,  Boring-Bars  and  Reamers. 

BOEING-BARS  AND   REAMERS. 

In  this  chapter  will  be  found  much  information,  compiled 
from  personal  experience,  the  columns  of  technical  journals  and 
notebooks  of  fellow  mechanics — which  will  assist  the  tool-maker 
in  the  designing  and  constructing  of  any  special  small  tools 
which  may  be  required  for  special  work  in  the  line  of  drilling, 
counter-boring  and  boring. 

DEEP-HOLE  DRILLING. 

*  The  process  of  drilling  deep  holes  in  metal  is  a  familiar  one 
in  many  shops,  particularly  where  firearms  are  manufactured  or 
heavy  ordnance  is  constructed.  Since  the  adoption  of  hollow 
spindles  for  lathes  and  other  machine  tools,  the  methods  for 
machining  the  bores  of  guns  have  been  employed  in  machine- 
tool  shops  for  drilling  these  spindles ;  and  through  this  and  the 
other  means  the  principles  of  the  operation  have  become  better 
understood.  It  is  not  an  easy  matter,  however,  even  with  the 
best  appliance,  to  drill  or  bore  a  deep  hole,  smooth  and  round,  of 
exactly  the  required  diameter  from  end  to  end,  and  perfectly 
straight.  While  many  mechanics  are  familiar  in  a  general  way 
with  the  methods  and  tools  for  doing  this  work,  some  specific 
information  upon  the  subject  will  be  appreciated  by  those  who 
have  not  had  actual  experience  in  deep-hole  drilling. 

It  is  known  that  a  long  or  deep  hole — that  is,  one  long  in 

proportion  to  its  diameter — is  best  roughed  out  and  finished  by 

using  a  tool  on  the  end  of  a  long  bar,  which  enters  the  work 

from  one  end.     This  is  true  whether  drilling  into  solid  metal  or 

boring  and  reaming  a  hole  that  has  already  been  drilled  or  bored 

*  "Machinery." 
244 


INTERCHANGEABLE  MANUFACTURING. 


245 


out.  A  boring-bar  which  extends  through  the  piece  and  on 
which  is  either  a  stationary  or  a  travelling  head,  is  not  satisfac- 
tory for  very  long  work,  owing  to  the  spring  and  deflection  of 
the  bar,  which  is  made  worse  by  the  fact  that  the  bar  must  be 
enough  smaller  than  the  bore  to  allow  room  for  the  cutter-head. 
While  a  long  hole  may  sometimes  be  finished  satisfactorily  by 
means  of  such  a  boring-bar,  by  packing  the  cutter-head  with 
wooden  blocks  which  just  fill  the  part  of  the  bore  that  has  been 
machined  and  so  support  the  bar,  the  method  is  fundamentally 
wrong  for  long  work. 

THE  TWIST-DEILL. 

The  modern  twist-drill  accomplishes  all  that  is  attained  by 
the  arrangement  in  Fig.  268,  and  in  addition  can  be  ground 


Fig.  268. 


without  seriously  affecting  the  rake,  and  will  free  itself  from 
chips  more  readily,*  owing  to  its  spiral  flutes.  The  lands  of  a 
twist-drill  present  a  large  cylindrical  surface  to  bear  against  the 
sides  of  the  hole  and  take  the  side-thrust.  If  the  drill  is  also 
guided  by  a  hardened  bushing,  at  the  point  where  it  enters  the 


OIL  PIPE  FROM  PUMP 


OIL  AND 
CHIPS  RETURN 
THROUGH  PIPE 


FIG.  269. 


metal,  as  in  the  case  of  jig  work,  the  drill  will  have  very  little 
chance  to  deflect  and  the  hole  will  be  accurately  located  and  will 
be  quite  true  and  straight. 


2J.6  TOOL-MAKING  AND 

The  twist-drill  in  modified  form  is  also  employed  for  deep 
hole  drilling.  The  hollow  drill  shown  in  Fig.  268,  and  intro- 
duced by  the  Morse  Twist-Drill  Co.,  New  Bedford,  Mass.,  is 
adapted  for  this  purpose,  and  in  Fig.  269  is  the  arrangement  rec- 
ommended by  this  company  for  feeding  the  drill  into  the  work. 
The  drill  has  a  hole  lengthwise  through  the  shank,  connecting 
with  the  grooves  in  the  drill.  The  shank  can  be  threaded  and 
fitted  to  a  metal  tube  which  acts  as  a  boring-bar  and  through 
which  the  chips  and  oil  may  pass  from  the  point  of  the  drill. 
Oil  is  conveyed  to  the  point  on  the  outside  of  the  tube,  as  shown 
in  Fig.  269. 

In  using  the  hollow  drill  the  hole  is  first  started  by  means  of 
a  short  drill  of  the  size  of  hole  desired,  and  drilled  to  a  depth 
equal  to  the  length  of  the  hollow  drill  to  be  employed.  The 
body  of  the  hollow  drill  acts  as  a  stuffing,  compelling  the  oil  to 
follow  the  grooves  and  the  chips  to  fall  out  through  the  hollow 
shank.  The  methods  of  supporting  and  driving  the  work,  and 
of  feeding  the  drill,  are  clearly  shown  in  Fig.  269.  Drills  of 
this  type  are  regularly  manufactured  in  sizes  up  to  three  inches 
in  diameter  by  the  Morse  Twist-Drill  Co.  It  is  stated  that  the 
best  results  are  obtained  when  drilling  crucible  steel  by  revolv- 
ing the  drill  twenty  feet  per  minute,  with  a  feed  of  0.0025-inch 
per  revolution,  while  machine  steel  will  admit  of  a  speed  of 
forty  feet  per  minute,  and  a  feed  of  0.0035-inch  per  revolution. 

NUMBER   OF   CUTTING-EDGES   DESIRABLE. 

When  drilling  a  hole  out  of  solid  stock,  some  type  of  drill 
having  two  lips  or  cutting-edges  is  usually  the  most  feasible, 
and  probably  nothing  will  be  devised  that  on  the  whole  surpasses 
the  twist-drill  for  such  work.  An  end-mill  can  be  used  for  drill- 
ing if  it  has  a  "centre  cut,"  aud  it  will  presently  be  explained 
how  a  tool  with  a  single  cutting-edge  may  be  advantageously 
employed,  particularly  for  deep -hole  drilling.  The  familiar 
D -drill  is  of  this  type,  and  also  its  modification  as  used  by  Pratt 
&  Whitney,  in  drilling  gun -barrels. 

When  it  comes  to  truing  up  or  enlarging  a  hole  previously 
drilled  or  bored,  the  two-lip  drill  is  not  suitable  in  any  of  its 


INTERCHANGEABLE  MANUFA CTTJBING. 


247 


forms.  For  boring  a  true  hole,  nothing  can  surpass  a  single- 
pointed  boring -tool,  the  ideal  condition  for  finishing  a  hole  being 
when  the  cutting-point  is  a  real  diamond,  or  a  rotating  wheel  of 
abrasive  material. 

It  is  obvious  that  when  a  hard  or  soft  spot  is  encountered  in 
boring  with  a  tool  having  a  single  cutting-edge,  only  that  par- 
ticular place  is  affected  by  the  spring  of  the  tool ;  while  with  a 


Fig.  270. 


Fig.  271. 


Fig.  272. 


Fig.  273. 


double-cutter,  as  shown  in  Fig.  270,  any  deflection  due  to  irregu- 
larities, such  as  at  a  or  b,  will  cause  the  tool  to  spring  and  the 
cutting-edge  on  the  opposite  side  to  introduce  similar  irregulari- 
ties in  the  opposite  side  of  the  hole.  This  is  one  objection  to 
the  two-lip  drill  for  accurate  work.    * 

With  three  points  the  tool  is  somewhat  better  supported  when 
a  high  place  is  countered,  as  at  Fig.  271,  and  when  a  cutting- 
point  strikes  a  low  place,  the  other  two  edges  are  not  moved 
away  from  their  position  so  much,  if  they  are  opposite  the  first 
edge.  Hence  a  tool  with  three  edges  should  prove  better  than 
one  with  two,  and  one  with  four,  Fig.  272,  being  better  sup- 
ported, is  better  on  this  account  than  one  with  three,  but  has  the 
disadvantage  of  opposite  cutters.  Five  edges,  Fig.  273,  ought 
to  give  even  better  results. 

In  general  it  may  be  said  that  in  boring  the  best  results  are 
obtained  when  the  tool  has  a  single  cutting-edge,  but  if  it  is  de- 
sirable to  have  more  cutting -edges,  a  tool  with  several  will  be 
more  satisfactory  than  one  with  only  two.  Any  machinist  who 
has  tried  to  true  up  the  taper  hole  in  a  lathe -spindle,  first  by 
boring  and  then  by  reaming,  will  appreciate  the  superiority  of 
the  boring-tool  over  the  multiblade  reamer.  A  reamer  some- 
times refuses  to  produce  a  perfectly  round  hole  and  will  do  this 


248 


TOOL-MAKING  AND 


whether  the  number  of  teeth  is  odd  or  even,  and  this  can  only  be 
prevented  by  spacing  unequally  or  "staggering." 

ADVANTAGES   OF   THE  END-CUT. 

One  trouble  with  reamers,  however,  is  that  the  teeth  neces- 
sarily cut  on  their  side  edges  instead  of  on  their  ends,  and  the 
whole  effect  of  any  uuevenness  in  the  hole  is  to  crowd  the  reamer 
to  one  side.  The  same  condition  exists  to  a  less  extent  with  a 
flat  or  twist-drill  where  the  cutting-edges  are  at  an  angle  with  the 
centre  line,  and  the  resultant  of  any  unusual  pressure  is  felt 
partly  as  a  side-thrust  and  partly  as  an  end-thrust.  Now,  by 
making  a  drill  to  cut  squarely  on  its  end,  and  but  very  little  or 
not  at  all  on  its  sides,  the  side-thrust  is  mostly  done  away  with. 

In  Fig.  274  is  a  boring-tool,  with  a  single  cutting-edge,  which 
cuts  on  its  end  and  is  capable  of  drilling  a  true  hole  in  solid 
metal.  It  was  illustrated  in  the  August,  1896,  number  of  "Ma- 
chinery."1 It  consists  of  a  round,  tool-steel  bar,  with  one  end 
flattened  and  ground  to  form  a  cutting-edge,  as  shown.  It  is  de- 
signed to  be  held  in  the  tool-post  of  the  lathe,  in  a  position  per- 


FiG.  274. 


pendicular  to  the  face-plate.  The  inner  edge,  or  corner  of  the 
cutting-edge,  should  be  slightly  rounded,  to  help  support  the 
cutter  and  prevent  chattering,  and  the  width  A  of  the  cutting- 
edge  should  be  from  ■£%-  to  -fa  -inch  less  than  the  radius  of  the 
hole  to  be  drilled. 


INTERCHANGEABLE  MANUFACTURING. 


249 


DKILLING  DEEP   HOLES   BY   THE   PBATT   & 
WHITNEY  METHOD. 

A  highly  satisfactory  drill  for  use  in  drilling  deep  holes  is 
one  brought  out  by  the  Pratt  &  Whitney  Co. ,  principally  for  use 
in  connection  with  their  gun-barrel  drilling-machines.  The  tool 
in  question  is  a  development  of  the  old  D  or  "hognose"  drill, 

x 


FIG.  275. 


which  has  one  cutting-lip  only.  It  is  carefully  ground  on  the 
outside  and  is  supplied  with  an  oil -duct  through  which  oil  at 
high  pressure  may  be  brought  direct  to  cutting-edge.  Referring 
to  Fig.  275,  A  is  the  cutting-edge,  B  the  oil-duct,  C  the  chip- 
groove. 

In  the  milling  the  latter  groove  is  brought  directly  to  the 
centre,  so  that  in  this  respect  the  drill  is  very  free-cutting  as 
compared  with  the  ordinary  two-lip  twist-drill,  which  has  a  cen- 
tral web.  In  the  end  view  the  shape  of  the  chip-groove  is  clearly 
indicated.  The  cutting-edge  A  is  radial  and  the  bottom  of  the 
groove  touches  the  centre  line  x  y. 

In  sharpening  the  drill  the  high  point,  or  part  first  entering 
the  work,  is  not  in  the  centre,  as  is  usually  the  case  in  drills,  but 
as  per  Fig.  275,  in  which  i>  is  a  cross-section  of  work  being 
drilled  and  E  the  high  point  of  drill.  Grinding  the  drill  in  this 
manner  is  one  of  the  reasons  for  its  running  true  or  straight,  the 
teat  F  on  the  work  acting  as  a  support  to  the  drill,  which,  owing 
to  its  periphery  being  partly  relieved,  would  have  a  tendency  to 
travel  in  a  curve  away  from  its  cutting-side.  The  piece  being 
drilled  is  run  at  very  high  speed,  the  periphery  speed  at  the  outer 
diameter  of  the  hole  running  as  high  as  130  feet  per  minute  on 
machine  steel.     The  feed,  however,  is  quite  fine. 


250 


TOOL-MAKING  AND 


These  tools  are  made  of  high-grade  steel  and  left  very  hard, 
so  that  the  fine  feed  has  little  tendency  to  glaze  the  cutting-edge. 

In  practice,  the  piece  being  drilled  is  held  and  revolved  at 
one  end  by  a  suitable  chuck  on  the  live  spindle  of  the  machine, 
while  the  other  end,  which  should  be  turned  perfectly  true,  runs 
in  a  stationary  bushing  having  at  its  outer  end  a  hole  of  the  di- 


ns. 276. 


ameter  of  the  drill.  The  drill  enters  the  work  through  the  bush- 
ing and  is  thus  started  perfectly  true.  See  Fig.  276,  in  which  A 
represents  the  chuck,  B  the  work,  C  the  bushing,  D  the  support 
for  holding  the  bushing,  E  the  drill. 

Through  the  oil -duct  of  the  drill  oil  is  forced  at  a  pressure 
varying  with  its  diameter  from  one  hundred  and  fifty  to  two 
hundred  pounds  per  square  inch.  After  passing  the  cutting- 
edge  the  oil  returns  to  the  reservoir  by  the  chip-groove  C,  Fig. 
275,  forcing  chips  along  in  its  travel.  In  drills  of  large  diame- 
ter, especially  when  working  on  tough,  stringy  material,  the  cut- 
ting-edge is  usually  ground  so  as  to  produce  a  number  of  shav- 


FiG.  277. 

ings,  instead  of  one  the  full  width  of  the  cutting-lip,  so  that  no 
trouble  is  experienced  in  getting  the  chips  out  of  the  way.  The 
oil,  of  course,  is  used  over  and  over  again,  and  with  a  large  res- 
ervoir will  be  kept  quite  cool. 

The  drill  is  made  up  of  the  drill-tip  and  shank,  the  tip  vary- 
ing in  length  from  four  inches  to  eight  inches,  while  the  length 
of  shank  is  determined  by  the  depth  of  hole  that  is  to  be  drilled. 
Fig.  277  will  clearly  illustrate  the  construction  of  a  small,  com- 
plete drill,  A  being  the  tip,  C  the  shank,  and  D  the  oil-duct. 


INTERCHANGEABLE  MANUFACTURING. 


251 


The  shanks  on  small  drills  are  made  from  steel  tubing  rolled  as 
per  cross-section  a  a.  The  tip  is  carefully  fitted  and  soldered  to 
the  shank,  which,  it  should  be  noted,  is  a  little  smaller  in  diameter 
than  the  tip.     The  shank,  with  oil  under  pressure,  is  very  stiff. 

The  relief  or  clearance  to  the  cutting-edge  of  the  drill,  the 
amount  of  "high-point"  of  the  drill  should  be  off  centre,  and 
the  number  of  rings  on  the  end  of  the  drill  depend  entirely  upon 
the  material  that  is  to  be  drilled.     For  instance,  on  very  soft 


Fig.  278 

stock  the  supporting  rest  should  be  more  substantial  than  on 
hard  spindle  or  gun  steel,  so  that  it  is  evident  that  on  soft  stock 
the  high  point  should  be  off  centre,  or  much  nearer  to  the  outer 
diameter  than  on  hard  stock. 

Fig.  278  is  a  sketch  of  a  3-inch  drill,  and  the  reader  will  ob- 
tain a  very  clear  idea  from  same  of  the  appearance  of  the  tool 
we  have  described.  This  figure  illustrates  a  drill  ground  on  the 
end  so  as  to  produce  several  shavings. 


BOEING  HOLLOW   SPINDLES   WITH   A   HOLLOW 

DEILL. 

*  In  boring  the  inner  tubes  of  steel  guns  of  large  calibre,  it 
has  long  been  the  practice  to  bore  them  with  a  hollow  drill, 

*  "  American  Machinist. " 


252 


TOOL-MAKING  AND 


which 
moved 


leaves  a  core  in  the  centre,  so  that  the  entire  metal  re- 
is  not  converted  into  chips,  but  only  what  might  be 
termed  a  shell  of  it,  the  outside  diameter  of  this 
shell  being  practically  equal  to  the  bore  and  the 
inner  diameter  being  enough  smaller  to  leave  a 
reasonable  thickness  for  the  drill. 

At  the  works  of  Schneider  &  Co. ,  at  Cruesot, 
France,  gun  tubes  are  bored  ou  this  plan,  and  it  is 
likely  that  the  same  plan  is  followed  at  Krupp's. 
It  has  not,  so  far  as  known,  however,  been  ap- 
plied to  the  boring  of  hollow  spindles  for  ma- 
chine tools  until  very  recently,  when  it  was  found 
in  use  in  the  shops  of  Mr.  Dietz  in  Cincinnati, 
Mr.  Dietz 's  shop  being  operated  in  connection 
with  that  of  the  Lodge  &  Shipley  Machine  Tool 
Company,  and  upon  certain  sizes  of  their  lathes. 
Mr.  Dietz  uses  in  a  boring- machine  of  the  usual 
type  a  drill  made  like  the  sketch,  Fig.  279, 
which  is  a  hollow  cylinder  with  a  T3T-inch  pipe 
for  lubrication,  and  the  cutter  is  located  as  shown, 
inclined  somewhat  to  the  axial  plane  in  order 
to  give  a  top  rake  and  with  the  edge  gashed  in 
order  to  break  up  the  chips  and  allow  them 
to  be  washed  out  through  the  groove  from  one 
end,  and  then  reversed  and  the  boring  completed 
from  the  other  end.  This  leaves  a  core  of  metal 
which,  as  it  is  worth  a  considerable  amount,  is 
well  worth  saving,  to  say  nothing  of  the  fact 
that  the  boring  is  more  easily  done  and  with  less 
strain  upon  the  machine  by  this  plan  than  where 
all  the  metal  is  reduced  to  chips. 

DEILL  NOTES. 


Fig.  279. 


As  a  rule,  the  cutting-edges  of  twist-drills 
are  formed  with  a  cutter  of  correct  form  to  pro- 
duce a  radial  line  of  cutting-edge ;  thus  a  different  form  of  cutter 
is  required  for  milling  the  flutes  of  straight- flute  drills. 


INTERCHANGEABLE  MANUFACTURING.         253 

Drills  are  generally  made  of  0.002-inch  or  0. 993-inch  taper 
per  foot  for  clearance,  and  have  the  major  part  of  land  on  the 
periphery  ground  away  for  the  same  purpose,  about  0.003-inch 
on  a  side. 

Drills  for  brass  should  be  made  with  straight  flutes ;  those  for 
cast-iron  and  tool  steel  should  in  those  cases  have  spiral  flutes  at 
an  angle  of  about  sixteen  degrees ;  soft  steel,  twenty-two  degrees. 

Chucking-drills,  for  use  on  cored  holes,  or  as  followers  of 
solid  twist-drills,  are  quite  often  provided  with  from  three  to 
eight  flutes ;  the  latter,  on  large  work,  are  very  efficient.  Care 
should  be  taken,  in  grinding,  to  insure  all  teeth  cutting  simulta- 
neously.    These  tools  are  made  of  solid,  shell,  and  inserted  type. 

The  inserted  type  are  preferable  for  straight  flutes  over  2f 
inches,  and  for  angular  flutes  over  4  inches,  on  account  of  cost. 

For  drilling  a  large  hole  in  a  spindle  the  latter  should  be  sup- 
ported in  a  back  rest,  and  the  drill  entered  through  a  drill-bush- 
ing to  start  perfectly  true.  Then,  by  using  a  drill  with  one  cut- 
ting-edge and  ground  on  the  outside,  a  long,  straight  hole  may 
be  readily  produced.  An  ordinary  twist-drill  will  do  practically 
the  same  if  the  centre  is  made  female,  the  only  objection  being 
that  this  form  is  much  more  difficult  to  grind. 

CIRCULAR  FORMING-TOOLS. 

Circular  forming-tools  for  machine  steel  and  cast-  iron  should 
have  a  generous  amount  of  clearance. 

Care  must  be  taken  on  particular  forms,  when  forming-cut- 
ters are  not  on  centre,  that  they  are  formed  with  this  point  taken 
into  consideration. 

Circular  threading-tools  for  inside  threading  must  be  much 
smaller  than  the  work ;  about  one-third  is  the  proper  practice. 

Care  should  be  exercised  to  use  a  correct  angle  of  chaser. 

PLAIN  FORMING-TOOLS. 

Plain  forming  tools  should  have  a  clearance  of  from  six  and 
one-half  to  ten  degrees. 

Rake :  Machine  steel,  eight  to  thirteen  degrees. 
Rake:  Tool-steel,  medium,  six  to  nine  degrees. 
Rake:  Brass,  none. 


254  TOOL-MAKING  AND 

The  clearance  on  tools  for  brass  is  quite  often  stoned  off  its 
cutting-edge  to  prevent  "biting  in"  (due  to  ease  in  cutting)  and 
then  chattering  (due  to  great  thickness  of  chip  and  consequent 
difficulty  in  severing).  The  "stoning  off"  also  tends  to  act  as  a 
support  for  the  cutter. 

FACING. 

For  steel  and  cast-iron,  cutters  with  from  six  to  twelve  de- 
grees rake  cut  very  freely,  The  clearance  should  be  from  three 
and  one-third  to  ten  degrees ;  when  there  is  any  tendency  to  chat- 
ter, the  cutting-edge  should  be  oil-stoned  on  clearance-face  suffi- 
ciently to  prevent  " biting  in."  On  very  broad  work  it  often 
becomes  necessary  to  make  cutters  without  any  rake  or  angle, 
but  allow  scraping,  to  prevent  chatter. 

In  practice  it  is  found  advantageous  to  place  cutter  ahead  of 
centre,  exposing  a  larger  cutting-edge  to  work,  giving  thinner 
chip. 

In  multiple  or  inserted  cutter-heads,  it  is  well  to  unevenly 
space  the  cutters ;  as  a  precaution  against  chattering,  have  the 
cutters  "staggered." 

Use  machines  with  large  bearings,  and  with  chucks  close  to 
same,  for  good  results. 

COTXNTEEBOBING. 

For  cast-iron  and  steel,  counterbores  are  generally  made 
with  ten  to  sixteen-degree  angles,  i.e.,  spiral;  for  brass  they  are 
cut  straight.  Clearance  is  from  five  to  ten  degrees.  On  brass, 
"stone  "  the  clearance -edge  to  prevent  chattering. 

Counterbores  internally  lubricated  are  recommended  for  steel 
for  use  to  depth  of  one-half  of  the  diameter  or  more. 

Angle- clearance  on  all  tools  must  be  more  than  spiral  gener- 
ated by  feed  at  smallest  diameter  of  cutting-point,  plus  suffi- 
cient to  be  really  forced  to  work  (about  three  degrees). 

COUNTEBBOBES. 

As  a  rule  counterbores  should  be  made  with  a  hole  chucked 
at  the  cuttiug-end  several  sizes  below  the  hole  that  is  to  guide 
the  counterboring  tool. 


INTERCHANGEABLE  MANUFACTURING.         255 

Then  the  guides  used  at  the  cutting-end  may  be  of  many  sizes, 
and  fit  many -sized  holes.  The  shanks  of  the  guides,  or  the  ends 
that  enter  the  holes,  should  be  all  of  one  size,  and  should  be  fitted 
to  force  lightly  in  so  they  may  be  readily  removed  from  the  body 
of  the  tool  and  others  inserted  in  their  place  to  fit  a  hole  of  an- 
other size.  The  upper  portions  of  these  guides  are  turned  up  to 
a  shoulder,  and  to  about  half  an  inch  or  less  from  the  outside,  or 
according  to  the  size  of  the  tool.  This  also  gives  the  workman  a 
better  chance  to  file  the  cutting-end  or  lips  to  a  perfect  and  true 
edge.  The  lips  on  their  sides  may  be  an  inch  or  less  in  length, 
according  to  their  diameter,  and  they  should  be  milled  out 
diagonally  in  order  to  give  a  shaving  cut  and  also  a  better  clear- 
ance for  the  chips. 

BEAMING  HOLES  IN  THE  TUBBET-LATHE. 

To  ream  holes  uniform  in  diameter  in  the  turret-lathe  or 
monitor,  it  is  necessary  that  there  shall  be  in  all  cases  an  equal 
amount  of  metal  for  the  reamer  to  remove.  To  insure  this  con- 
dition two  reamers,  a  rougher,  and  a  finisher  should  be  used. 
The  hole,  first,  if  cored,  should  be  bored  by  a  single  or  a  double 
edge  boring-tool  to  insure  a  hole  comparatively  true. 

BEAMING  HOLES   IN  THIN  DISKS. 

For  reaming  holes  in  thin  disks  a  reamer  of  the  "rose  type  " 
should  be  used,  as  it  will  be  self-supporting,  and  the  possibility 
of  enlarging  the  hole  by  its  weight  will  be  obviated. 

MACHINE-BEAMING  WITH  A  "FLOATING"  BEAMEB. 

Very  often,  when  machine-reaming,  the  finishing  reamer  is 
supported  loosely  in  its  holder,  and  allowed  to  find  its  own  centre 
by  following  the  true  or  concentric 

J  °  BUSHING  /PIN 

hole   left    by  the    preceding  tools.        \      '^JHI    «„„„„. 

This  is  usually  done  by  having  a    (^       _         '     I     j 
"  floating  "  reamer  with  a  pin  entered       ^— — J*-— ' 

to  L  Fig.  280. 

through  the  holder  and  the  reamer 

in  the  back  end,  the  hole  in  the  reamer  being  made  larger  than 
the  pin,  thus  allowing  the  reamer  to  find  its  own  centre.  The 
construction  of  a  reamer  of  this  type  is  shown  in  Fig.  280. 


256  TOOL-MAKING  AND 

BEAMING   TAPER   HOLES   IN   CAST-IRON. 

For  reaming  taper  holes  in  cast-iron  machine  parts  in  the 
turret-lathe,  particularly  those  parts  from  which  large  amounts 
of  stock  are  to  be  removed,  a  reamer  of  the  construction  shown 
in  Fig.  281  should  be  used.  As  will  be  seen,  this  reamer  has 
only  three  blades.  The  flutes  in  a  reamer  of  this  kind  should 
be  Cut  as  deep  as  the  diameter  of  the  stock  will  allow,  and  the 
blade  should  be  given  very  little  clearance.  The  clearance  that 
is  necessary  may  be  provided  by  grinding  the  blades  convex,  as 
shown,  instead  of  flat  or  hollow,  as  is  usually  done.  When  a 
considerable  amount  of  stock  is  to  be  removed,  a  reamer  of  this 
type  will  work  very  well.  The  preliminary  work  re- 
quired, with  regard  to  the  other  boring-tools,  before 
the  one  shown  should  be  used,  consists  of  boring  a 
hole  to  the  right  size  for  the  small  end  of  the  reamer, 

Fir    ^81 

after  which  the  three- blade  finishing  reamer  may 
be  used  to  finish  an  irregular  surface  from  three  to  six  inches 
long,  feeding  the  reamer  in  rapidly  without  danger  of  catching, 
chattering,  or  roughing  up.  In  one  large  machine-manufactur- 
ing establishment  thousands  of  holes  are  finished  every  day  with 
reamers  of  this  type,  attaining  the  best  results  in  the  shortest 
time  with  the  least  trouble. 

TAPER-REAMING  IN   THE   SCREW-MACHINE. 

To  do  taper-reaming  in  the  screw-machine,  use  reamers  taper- 
ing from  2  J  inches  per  foot  upward,  and  the  best  results  will  be 
accomplished.  For  very  accurate  work  the  reamers  will  give 
better  satisfaction  if  made  with  left-hand  spiral  flutes. 

For  want  of  proper  grinding  facilities,  however,  this  is  not 
done  in  many  shops. 

To  ream  slightly  tapering  holes  of  small  diameters,  the  reamer 
should  always  be  made  with  the  teeth  "staggered"  in  spacing, 
and  each  flute  a  left-hand  spiral  of  different  pitch. 

Very  often  roughing-,  taper-,  and  forming -reamers  for  steel 
are  finished  with  an  undercut.  They  remove  material  very 
rapidly. 


INTERCHANGEABLE  MANUFACTURING.         257 


EEAMEES  FOE  BBOJECTILES. 

In  the  production  of  projectiles,  forming-,  taper-,  and  curv- 
ing reamers  are  used.  For  this  work  roughing-reamers  should 
be  finished  with  a  left-hand  spiral  thread  nicked  around,  while 
the  finishing  ones  should  be  finished  straight.  The  finishing  of 
taper-reamers. with  left-hand  spiral  flutes  for  this  work  prevents 
their  being  drawn  in  while  cutting. 

TAFEE   OF   BOSE-BEAMEBS. 

Eose-reamers  should  be  given  taper  for  clearance,  about 
0.003-iuch  to  the  foot  will  be  enough.  This  will  prevent  them 
from  roughing  up  the  hole  and  allow  of  finishing  holes  straight 
and  correct  in  diameters. 

CENTEE-EEAMEES. 

Centre -reamers  should  be  finished  to  an  angle  of  sixty  de- 
grees, and  the  work  centres  of  all  machines  to  the  same.  The 
centres  should  be  hardened  and  ground  in  their  machines  by 
means  of  a  good  tool-post  grinder  to  gauge,  as  it  is  impossible  to 
do  good  work  on  defective  centres. 

EEAMEES  FOE  BABBIT. 

For  reaming  babbit,  the  reamer  may  be  of  the  usual  form, 
except  that  the  edges  of  the  blades  should  be  ground  taper  for 
about  ^-inch  from  the  end.  Sometimes  reamers  for  such  mate- 
rial are  finished  with  left-hand  spiral  flutes,  which  contributes 
to  finishing  a  smooth  hole  free  from  lines  and  rings. 

BEAMING  HOLES  IN  TWO   KINDS   OF   METAL. 

Not  infrequently  it  is  necessary  to  bore  a  hole  in  a  part  which 
is  made  up  of  two  kinds  of  metal,  such  as  brass  and  cast-iron, 
for  instance.  This  is  a  rather  difficult  thing  to  accomplish  suc- 
cessfully, as  the  hole  will  usually  be  larger  in  the  softer  side  of 

the  metal  than  in  the  harder.     However,  by  using  a  reamer  with 
17 


258 


TOOL-MAKING  AND 


a  cutter-face  of  the  construction  shown  in  Fig.  282,  and  cutting 
an  uneven  number  of  staggered  flutes  in  it,  satisfactory  results 
will  be  attained.  Have  the  angle  of  the  cutter- 
face  about  ten  degrees.  In  using  this  reamer, 
first  bore  the  hole  with  the  usual  type  of  boring- 
tools  until  it  is  a  size  slightly  below  that  re- 
quired, then  chamfer  the  edges  of  the  hole  on 
the  bard  side  and  feed  in  the  reamer,  lubricating  generously 
with  oil,  and  always  see  that  the  hard  side. of  the  work  is  out. 


Fig.  283. 


MACHINE-REAMING   OF   BRASS   PARTS. 

For  the  machine-reaming  of  brass  parts  some  make  their 
reamers  slightly  over  size,  but  this  is  wrong.  Instead,  a  reamer 
for  brass  should  be  ground  in  much  the  same  manner  as  a  turn- 
ing-tool for  brass  should  be — that  is,  in  place  of  a  radial  line  in 
the  centre,  as  in  most  other  reamers,  the  cutting-edges  should  be 
thrown  off  from  the  centre  at  an  angle 
of  about  twenty  degrees  out  of  the  radial 
line,  as  per  Fig.  283.  For  the  same  rea- 
son, in  turning  brass,  if  the  tool  is  ground 
straight  and  set  central  with  the  work, 
chattering  is  bound  to  occur.  If,  on  the 
contrary,  the  tool  is  reground  on  top  to 
an  angle  as  described  above,  running  toward  the  underside  of 
the  blade,  chattering  will  be  obviated  and  the  tool  will  cut  freely. 
Always  keep  the  cutting-edges  of  reamers  for  brass  as  sharp 
as  possible  by  "stoning,"  because  as  soon  as  the  cutting-edges 
become  slightly  dulled  they  will  bind  and  scream. 


Fig.  283. 


SQUARE  REAMERS  AND   EXPANSION  REAMERS. 

Fine  finishing  of  holes  in  brass  may  be  done  with  the  square 
reamer  or  "scraper."  Expansion  reamers  also  possess  many 
good  points,  but  few,  if  any,  can  be  expanded  and  adjusted  for 
sizing  without  the  cutting-edges  requiring  to  be  ground  before 
the  tool  can  be  used.  However,  there  are  some  in  which  the 
blades  will  expand  equally.  Even  if  it  is  necessary  to  grind  the 
expansion  reamers  when  changing  an  adjustment,  there  is  econ- 


INTERCHANGEABLE  MANUFACTURING.         259 

oiny  in  their  use  when  compared  with  the  cost  of  a  new  solid 
reamer,  especially  when  they  are  used  for  holes  of  large  diame- 
ters. A  long  hole  may  be  reamed  straight  by  pulling  back 
slightly  after  the  reamer  has  commenced  to  cut. 

BEAMING   SMALL   HOLES. 

For  machining  very  small  holes  in  steel  and  cast-iron,  ream- 
ers should  be  ground  straight,  while  for  brass  and  copper  they 
should  be  ground  slightly  back,  tapering  in  order  to  eliminate 
the  possibility  of  roughing  up  the  holes. 

Always  remember  that  on  reamers  for  steel  and  cast-iron  the 
teeth  should  be  on  centre,  while  for  brass,  copper,  and  similar 
metals  they  should  be  at  an  angle  of  twenty  degrees  off  the  radial 
line. 

Speeds  for  machine-reaming  should  usually  range  from  20  to 
25  per  cent,  lower  than  turning  and  drilling-speeds. 

"HOME-MADE"   EEAMEES. 

There  are  in  a  great  many  shops  numbers  of  "home-made" 
reamers  in  the  possession  of  the  men,  made  at  various  times  by 
the  mechanics,  without  due  regard  to  their  proper  construction. 
Eeamers  of  this  kind  should  never  be  used  for  fine  work,  as  they 
are  usually  defective.  For  instance,  the  flutes  are  too  shallow 
and  spaced  too  close,  and  often  they  are 
spaced  evenly  instead  of  being  staggered, 
or  they  have  an  even  number  of  teeth,  all 
of  which  is  wrong.     When  a  reamer  is  FlG  28i. 

evenly  spaced  it  will  chatter  as  soon  as  the 

cutting-edges  fall  into  the  notches  left  by  the  preceding  one.  A 
common  fault  with  "home-made"  reamers  is  that  they  are  given 
too  much  clearance,  thus  making  chattering  inevitable. 

HAND-BEAMING. 

In  hand-reaming  never  leave  more  than  0.003  of  stock  to  be 
removed,  no  matter  what  the  material  may  be.  On  the  contrary, 
for  machine-reaming,  not  less  than  -^  and  often  T^  should  be  left; 


2G0  TOOL-MAKING 

using  reamers  with  much  coarser  blades  than  the  usual  commer- 
cial ones,  and  formed  so  that  they  can  be  ground  on  the  points. 
Hand-reamers  for  use  in  boiler,  bridge  work,  etc. ,  should  be 
of  the  construction  shown  in  Fig.  284,  as  they  will  work  better 
than  the  usual  half-round  kind. 

INCREASING   THE   SIZE   OF   A  REAMER     WHEN 

WORN. 

To  increase  a  reamer  to  size  when  worn,  burnish  the  face  of 
each  tooth  with  a  hardened  burnisher,  which  can  be  made  from  a 
three-cornered  file  nicely  polished  on  the  corners.  This  will  in- 
crease the  size  from  two  to  ten  thousandths  in  diameter.  Then 
hone  back  to  the  required  size. 

To  make  a  tap  or  reamer  cut  larger  than  itself,  put  a  piece 
of  waste  in  one  flute,  enough  to  crowd  it  over,  and  cut  out  on  one 
side  only.  In  larger  sizes  (l|-inch  or  over)  put  a  strip  of  tin  on 
one  side  and  let  it  follow  the  tap  through. 


CHAPTER  XVIII. 

Broaches  and  Broaching. 
THE   OPERATION   OF   BROACHING. 

The  operation  of  broaching  may  be  classed  under  the  head 
of  punches  and  dies,  as  it  is  analogous  with  press-work.  In 
reality  the  broach  is  a  punch,  the  cored  or  drilled  holes  in  the 
work  to  be  machined  by  it  acting  as  a  die  and  guide  for  same. 
The  operation  of  broaching  has  had  great  develop- 
ment during  the  last  decade,  special  machines  and 
forms  of  tools  having  been  designed  to  further  the 
use  of  this  interesting  and  labor-saving  process  for 
the  finishing  of  work  which  it  was  formerly  thought 
to  be  impossible  to  finish  by  such  means. 

The  broach  as  a  tool  is  usually  used  for  finishing 
holes  which  have  been  previously  either  punched, 
cored,  drilled,  or  bored  in  metal,  the  shape  of  which 
may  be  round,  square,  or  any  irregular  shape  de- 
sired. Although  the  broach  can  be  used  to  advan- 
tage for  the  finishing  of  holes  by  setting  it  under 
an  ordinary  power-press,  an  arbor-press,  or  a  foot- 
or  screw-press,  the  operation  can  be  best  accom- 
plished in  a  press  specially  designed  for  the  pur- 
pose of  broaching.  A  press  of  this  sort  has  usu- 
ally an  adjustable  stroke  of  from  1^  to  12  inches. 

In  Fig.  285  we  show  a  sketch  of  a  broach  used 
for  finishing  a  cored  hole  in  a  rough  casting.  The 
tool  is  3  x  1  inches,  and  9  inches  in  length.  In  this  tool  the 
teeth  are  very  coarse  at  the  lower  end,  being  intended  for  re- 
moving the  bulk  of  the  stock  until  the  centre  of  the  broach  is 
reached,  when  the  teeth  are  sheared  in  the  opposite  direction, 
thus  breaking  the  chip  off.  The  teeth  in  the  broach  then  de- 
crease in  size  until  near  the  upper  end,  when  they  are  left  the 

261 


Fig.  285. 


262  TOOL-MAKING  AND 

one  size  for  about  two  inches  of  the  remaining  length,  thus  form- 
ing a  "sizer"  which  shaves  the  hole  to  a  standard  size  all  the 
way  through. 

In  forcing  a  broach  through  a  hole  it  may  be  best  driven  by 
a  "V"  brock,  which  should- be  secured  in  the  press-ram  in  much 
the  same  manner  as  a  punch  would  be.  Thus  when  the  press- 
ram  descends  the  broach  will  find  its  own  centre ;  while  the  lia- 
bility of  breaking  or  bending  the  broach  or  producing  an  im- 
perfect hole  will  be  obviated. 

In  order  to  broach  holes  of  considerable  length  in  a  press 
with  a  short  stroke,  the  work  may  be  satisfactorily  accomplished 
by  using  a  successive  number  of  blocks.  First  insert  the  broach 
in  the  hole  and  then  drive  it  down  into  the  same  for  the  full 
length  of  the  press-stroke.  Kext,  insert  a  block  of  the  same 
thickness  as  the  length  of  the  stroke  between  the  ram-face  and 
the  broach-end,  and  then  force  the  broach  in  a  further  distance ; 
repeating  the  operation  and  using  larger  blocks  until  the  desired 
length  of  drive  has  been  obtained.  By  this  method  it  may  be 
well  to  state  that  the  results  attained  will  not  equal  the  work 
performed  on  a  continuous  stroke-press,  as  the  stopping  of  the 
broach  when  partly  through  the  work  allows  the  metal  to  settle 
into  the  broach  teeth,  thus  increasing  the  tendency  to  bend  and 
break. 

To-day  there  are  on  the  market  any  number  of  machines 
which  have  been  specially  designed  for  broaching.  A  number 
of  these  machines  perform  the  operation  by  pulling  the  broach 
through  the  hole  instead  of  forcing  it  through. 

AN   INTEEESTING   JOB   OF   BBOACHING. 

Broaching  is  very  interesting  work.  For  some  work  the  best 
and  only  way  to  make  a  broach  is  in  one  piece;  while  for  other 
work  long  experience  has  taught  that  it  is  the  wrong  way.  To 
do  the  job  shown  in  the  sketch,  Fig.  286,  with  one  broach  would 
require  a  long  one,  and  that  would  cause  trouble;  for  a  broach 
of  sufficient  length  for  this  work  is  difficult  to  turn  and  mill, 
and  to  harden  and  draw,  owing  to  the  keyway  on  one  side  which 
will  cause  it  to  spring  in  hardening ;  it  would  be  an  advantage  if 
it  were  grooved  on  opposite  sides. 


INTERCHANGEABLE  MANUFACTURING. 


263 


The  hole  in  the  piece  shown  in  Fig.  286  is  broached  from  |- 
to  |i-inch — and  a  key  T]¥-inch  high  formed— and  is  afterward 
drifted  to  i-i-inch  at  the  bottom  and  f -inch  at  the  top ;  the  thick- 
ness of  the  piece  is  finch.  Over  250,000  pieces  have  been 
made  with  the  broaches  as  shown,  and  the  loss  in  broaches  and 
pieces  was  nothing  compared  with  the  loss  when  using  the  long 
broaches  first  made. 

The  stock  for  this  job  was  a  special  tough  tool  steel.  The 
broaches  are  shown  in  Figs.  287  to  291 ;  they  were  four  inches 
long  and  of  the  diameter  given.     Each  was  tapered  at  one  end 


FIG.  286. 


r-<j^ojsj)"  i*-»i  o-sbV'u.  _J  0.624"  U- -M  "/«     U— 
/No.  i\ 


»  A-     — i 


<&v 


■s 


576"  [^ — 


_J 


i. 


UD 


0.608     ■«-     7       T\ 

Front  Side 


Fig.  287.    Fig.  288.    Fig.  289.    Fig.  290.    Fig.  291. 


and  countersunk  at  the  other,  and  the  top,  or  male  end,  was 
milled  flat  on  one  side  (like  No.  4)  to  fit  the  punch-press  fixture, 
Fig.  292.  Xos.  1,  2,  and  3  have  five  teeth  per  inch,  and  No.  4 
has  six  teeth ;  it  will  also  be  noticed  the  latter  broach  is  left 
blank  at  one  end ;  this  will  be  explained  later. 

The  teeth  being  f-inch  from  the  end,  this  part  was  drawn  to  a 
blue  after  hardening.  This  was  very  important,  as  the  end  had 
a  tendency  to  crumble  and  break  out  and  thus  destroy  the  broach. 
The  end  was  drawn  by  dipping  in  hot  lead  after  the  broach  was 
hardened  and  drawn  to  a  straw  color.  For  cutting  tool  steel 
very  little  clearance  was  given  the  teeth ;  too  much  clearance 
would  cause  the  broach  to  cut  ragged. 


264 


TOOL-MAKING  AND 


The  ^-inch  hole  to  receive  the  end  of  the  first  broach  was 
drilled  in  the  stock,  and  the  other  end  of  the  broach  was  inserted 
in  the  hole  H  in  j>late  C,  Fig.  293.  To  the  plate  was  secured 
two  rods,  which  had  a  vertical  movement  in  plate  B,  light 
springs  keeping  plate  C  away  from  the  punch.  An  important 
feature  is  the  hole  H,  which  received  the  end  of  the  broach  and 
prevented  its  being  placed  in  the  wrong  position,  as  each  broach 
had  to  follow  exact,  owing  to  the  keyway. 

A  clearance  (shown  at  D)  on  each  broach  served  to  guide  an 
end  of  the  broach  while  entering.  After  the  first  broach  was 
entered  and  forced  into  the  work  by  the  press,   the  upper  end 


MamvMMmr — t     <;Mm 

PUNCH   PRESS  PLATE_ 
FIG.  292. 


projected  above  the  work  to  receive  the  second  broach,  which 
was  in  turn  punched  through,  being  followed  by  broach  No.  3, 
and  the  latter  by  No.  4.  If  teeth  were  cut  the  full  length  of  the 
last  broach,  it  would  stick  in  the  work.  To  overcome  this  it  was 
cleared  at  the  end,  as  shown,  so  that  when  punched  down  to  the 
end  of  the  stroke  the  broach  would  fall  through.  The  work  in 
making  broaches  of  this  length  is  simple,  as  they  are  easy  to 
turn,  harden,  draw,  and  grind. 

In  punch  A  a  hardened -steel  plate,  D,  was  inserted,  as  at  this 
point  any  wear  would  cause  the  broach  to  twist  and  spoil  the 
key.     This  is  made  a  driving  fit,  and  can  be  replaced  at  any 


INTERCHANGEABLE  MANUFA  CTUBING. 


265 


time.  The  finished  hole,  Fig.  286,  was  drifted  cold ;  and  owing 
to  the  quality  of  the  stock  was  a  neat  piece  of  work.  Figs.  293 
and  294  show  the  drift  and  the  punch-press  fixtures.     The  punch 


^A 


Fig.  293. 


Fig.  294. 


for  putting  in  the  drift  had  a  steel  insert,  the  same  as  D  in  A. 
It  is  very  important  in  making  broaches  that  the  stock  be  thor- 
oughly annealed,  and  when  broaching  use  nothing  but  the  very 
best  of  oil. 


SOME   POINTS   ABOUT   BEOACHES   AND   BROACHING. 

In  order  to  secure  good  results  in  broaching  the  bottom  of 
the  tool  used  should  be  hollowed  out  somewhat,  so  that  a  nice 
clean  chip  will  be  cut  from  the  inside  of  the  hole,  and  so  that  the 
tendency  to  dodge  to  one  side  when  places  in  which  the  cored 
hole  is  rough  or  crooked  are  encountered  will  be  obviated.  The 
stripper  for  the  work  should  be  arranged  so  as  to  pull  off  square. 
Otherwise,  if  the  hole  is  a  long  one,  it  will  be  spoiled  when  the 
broach  is  pulled  out. 

The  special  presses  provided  for  broaching  are  usually  back- 
geared  and  very  powerful.  It  is  not  well  to  speed  the  press  too 
fast.     In  all  cases  use  oil  as  a  lubricant.     When  the  amount  of 


266 


TOOL-MAKING   AND 


stock  to  be  removed  is  considerable,  it  will  be  necessary  to  do 
the  work  in  two  operations ;  too  heavy  a  cut  having  a  tendency 
to  make  the  hole  rough.  Socket-wrenches  or  similar  fits  are 
easily  made  in  this  way.  If  the  cuts  are  made  light  enough,  it 
is  possible  to  broach  cast-iron  in  this  way,  using  for  this  purpose 
several  punches  or  broaches  of  different  sizes.  Such  punches 
should  be  slightly  larger  at  the  cutting  end,  and  for  the  finishing 
cut  or  last  operation— if  clear  through  the  piece — should  work 
into  a  die  or  the  tool  will  break  off  or  tear  away  the  lower  edge 
of  the  work.  The  temper  should  be  a  trifle  harder  than  that 
given  to  ordinary  punches  and  dies.  A  in  Fig.  295  shows  a  side 
view  of  a  broach  which  was  made  for  cutting  out  the  holes  in 
three  cast-steel  flanges  for  a  steamboat.  The  holes  had  been 
cored  out  of  a  f -inch  bolt  instead  of  a  f-inch ;  hence  the  necessity 
for  enlarging  them.     The  broach  was  made  with  six  steps,  as 


6__     ^4821 

%  SQUARE  STEEL 

„ 

/ 

\ 

6 

\ 

/ 

Fig.  29.5. 

shown  at  A,  and  with  the  steps  numbered  at  B.  Step  1  acts  as 
a  pilot  and  to  scrape  out  the  sand ;  step  2  cuts  on  four  sides  some- 
what, as  shown  at  C,  step  3  cuts  the  hole  slightly  larger  in  the 
same  manner ;  the  next  three  steps  cut  out  the  corners,  as  shown 
in  4,  5,  and  6. 

There  were  ninety  holes  in  all,  one-half  of  which  were  through 


took  about  three  hours  to  broach  them  out,  driving  the  broach 
with  a  sledge,  as  no  press  was  at  hand.  The  operation  of  mak- 
ing the  tool  took  about  one  and  one-half  hours  on  the  milling- 
machine,  using  an  end -mill. 


INTERCHANGEABLE  MANUFACTURING.         267 

BEO ACHING:   ITS   EELATION   TO   SHEET-METAL 

WOEK. 

Oberlin  Smith,  in  bis  "Press  Working  of  Metals,"  bas  given 
ns  tbe  following  in  regard  to  the  relation  of  the  word  "broach- 
ing "  to  sheet-metal  work : 

"...  The  word  '  broaching '  has  here  a  very  different 
meaning  from  that  given  it  by  the  machinist,  who  applies  it  to 
the  process  of  forcing  a  .piece  of  male  work  through  a  lower  cut- 
ting-die, or  pushing  a  cutting-punch  through  a  hole  in  female 
work,  thereby  shaving  it  to  a  given  size,  and  really  performing 
an  operation  analogous  to  planing  or  slotting.  In  cases  where 
he  uses  male  or  female  broaching-cutters  having  a  series  of  teeth 
following  each  other,  and  each  taking  off  its  own  chip,  his  work 
more  nearly  resembles  milling.  In  relation  to  sheet  metals  the 
word  broaching  means  smashing  the  work  thinner  by  forcing  it 
through  a  space  between  the  punch  and  die,  as  in  some  kinds  of 
tube-drawing,  which  again  is  the  same  as  wire-drawing,  if  we 
imagine  the  mandrel  to  be  a  part  of  the  tube.  In  the  case  in 
question  a  reduction  of  diameter  is  being  made  at  the  same  time 
as  the  thinning  of  the  metal  is  taking  place.  This  is  much  prac- 
tised in  cartridge -drawing,  especially  where  it  is  desirable  to 
keep  the  end  or  bottom  of  the  work  of  the  original  thickness. 
When  done,  the  bottom  remains  of  as  much  greater  thickness 
than  the  sides  as  happens  to  be  required  and  as  has  been  arranged 
for  in  choosing  the  thickness  of  the  sheet.  In  small  work  of  this 
kind  the  use  of  a  blank-holder,  or  upper  die,  is  abandoned  after 
the  first  one  or  two  draws,  as  the  metal  is  reduced  so  little  in 
diameter  in  proportion  to  its  thickness  that  the  wrinkles  have  no 
chance  to  form.  Even  if  incipient  wrinkles  do  form  they  are 
quickly  crushed  out  again  as  the  metal  is  squeezed  somewhat 
thinner.  In  this,  as  in  all  drawing,  however,  the  wrinkles  must 
never  be  allowed  to  get  big  enough  to  fold  over  upon  one  another. " 


CHAPTER  XIX. 

Shop  Use  of  Micrometer-Calipers  and  the  Height- 
Gauge. 

MICROMETEE-CALIPEES. 

In  the  accurate  production  of  duplicate  parts  as  carried  on 
to-day  in  the  economic  manufacture  of  machinery,  tools,  punches 
and  dies,  and  instruments  of  precision,  accurate  gauges  are  de- 
manded. For  years  the  average  machine-shop  got  along  with 
templets  and  gauges  of  sheet  steel,  so-called  "limit-gauges,"  of 
doubtful  accuracy  and  of  little  value,  as  they  were  carelessly 
made  and  used  with  indifference.  However,  we  are  pleased  to 
say,  this  state  of  affairs  has  passed  away;  and  the  increased  use 
of  the  micrometer-caliper  has  enriched  the  scrap  piles  of  many 
shops  with  collections  of  "snap"  and  "limit"  gauges,  "temp- 
lets "  and  "  reference  "  disks ;  has  increased  the  economic  produc- 
tion of  the  shops,  and  made  the  workmen  more  skilful. 

To  produce  accurate  work  the  skilled  machinist  or  tool-maker 
of  to-day  demands  as  a  first  requisite  a  means  of  measuring  his 
work  during  the  process  of  machining  it  to  the  required  size  and 
shape ;  and  this  requirement  is  filled  when  the  workman  is  sup- 
plied with  a  micrometer  caliper  and  the  feed-screws  of  the  ma- 
chine which  he  operates  are  fitted  with  graduated  disks.  Of  course 
it  must  not  be  inferred  from  this  that  braius  are  not  required 
along  with  these  gauges ;  or  that  an  indifferent  or  careless  work- 
man will  instantly  become  a  skilled  mechanic  upon  being  supplied 
with  a  micrometer.  However,  the  use  of  the  micrometer  will 
improve  the  poorest  workman ;  as  instead  of  guessing  he  will 
measure ;  he  will  use  his  eyes  and  think ;  thus  a  consequent  im- 
provement will  take  place. 

Among  shop  managers,  superintendents,  and  foremen,  the 
most  common  objection  raised  against  the  general  shop  use  of 
micrometers  is  that  they  are  too  light,  and  are  liable  to  get  out 

268 


INTERCHANGEABLE  MANUFACTURING.         269 

of  order  when  used  by  all  classes  of  help.  Now,  while  this  may 
occur,  there  is  hardly  any  excuse  for  it ;  any  man  that  is  trusted 
with  and  is  capable  of  turning  out'  accurate  work  can  be  safely 
trusted  to  use  a  micrometer  correctly.  To  be  sure  it  makes  a 
great  difference  how  the  tool  is  handled.  It  all  depends  upon  the 
workman's  sense  of  touch.  The  machinist,  as  a  rule,  wants  in- 
formation as  to  how  much  more  has  to  come  off  after  he  has 
taken  a  cut,  and  so  he  sometimes  forces  the  gauge  in  the  hope  of 
determining  by  the  sense  of  touch  how  much  remains  to  come 
off.  This  sense  of  touch  differs  in  mechanics  very  much.  In 
some  it  amounts  to  a  considerable  exertion  of  their  strength; 
these  are  the  one  who  spoil  the  gauges. 

With  the  micrometer  there  is  no  excuse  for  the  use  of  strength ; 
it  is  an  adjustable  gauge  aud  the  machinist  knows  by  reading  it 
when  the  work  has  been  reduced  to  the  size  desired.  He  knows 
also  that  he  may  run  the  screw  back  at  intervals  and  determine 
the  amounts  remaining  to  come  off ;  he  may  also  determine  the 
size  at  the  start ;  and  for  sizing  a  number  of  pieces  he  may  lock 
it  and  use  it  in  the  same  manner  as  he  would  a  snap -gauge.  In 
the  use  of  the  micrometer  the  mechanic  has  to  use  his  eyes  and 
brains  more,  and  his  strength  becomes  an  ineffective  factor  in 
the  attainment  of  the  results. 

It  is  very  easy  to  teach  bright  apprentices  and  operators  how 
to  use  micrometers ;  in  fact,  the  reading  of  them  to  the  one-thou- 
sandth of  an  inch  is  very  simple ;  while  their  reading  to  one-ten- 
thousandth  of  an  inch  can  be  learned  after  a  little  thought  and 
practice.  The  ease  with  which  workmen  in  general  learn  to  read 
and  use  these  gauges  can  be  inferred  from  the  fact  that  there  are 
any  number  of  small  shops — in  the  East  at  least — to  my  knowl- 
edge, in  which  accurate  work  is  turned  out,  where  nothing  in  the 
way  of  gauges  is  used  but  micrometers.  As  this  is  successfully 
done  on  a  small  scale,  I  can  see  no  reason  why  the  installation 
of  the  system  on  a  large  scale  should  present  difficulties. 

In  all  shops  in  which  micrometers  are  used  in  place  of  the 
obsolete  gauges,  or  in  shops  where  they  are  about  to  be  used,  a 
good  set  of  B.  &  S.  test  pieces,  either  end-measures  or  disks, 
should  be  provided ;  also  a  man  should  be  detailed  to  take  care 
of  the  adjustments  of  all  micrometers  in  the  shop ;  someone  who 


270 


TOOL-MAKING  AND 


is  skilled  iu  such  work  and  who  has  cultivated  a  delicate  sense  of 
touch.  In  shops  where  the  work  done  is  of  great  accuracy  and 
only  the  minimum  limit  of  error  is  allowable,  two  sets  of  test 
measures  should  be  provided ;  one  set  to  be  for  general  use  and 
the  other  for  occasional  reference  only.  The  new  micrometers 
should  be  given  to  the  most  skilled  men  for  use  on  the  finest 
work  only ;  while  those  micrometers  that  have  become  worn,  or 
are  to  a  certain  extent  inaccurate,  should  be  used  on  work  in 
which  a  greater  limit  of  error  is  allowable.  Above  all,  never 
use  generally  calipers  graduated  to  ten-thousandths,  where  fine 
measurements  are  not  necessary,  as  in  an  instrument  of  the  pre- 
cision of  this  class  a  wear  is  preceptible  and  important  which 
would  be  of  comparatively  slight  consequence  in  a  caliper  that  is 
graduated  to  be  read  only  in  thousandths. 


BEADING   MICROMETER-CALIPERS   TO   TEN- 
THOUSANDTHS   OF   AN  INCH. 

While  the  ordinary  reading  of  micrometers  is  pretty  gener- 
ally understood — i.e.,  reading  to  thousandths  of  an  inch — the 
reading  of  them  to  ten-thousandths  is  not.  For  the  benefit  of 
those  who  do  not  understand  this  I  explain  in  the  following 
how  to  do  it. 

In  Fig.  296  a  1-inch  B.  &  S.  micrometer-caliper  graduated  to 
read  to  ten-thousandths  of  an  inch  is  illustrated.     The  readings 


nTjTTnTJ 

THIMBLE 


Fig.  296. 


in  ten-thousandths  are  obtained  by  means  of  a  veriner  or  series 
of  divisions  on  the  barrel  of  the  caliper  on  the  side  shown  in  the 
cut.     These  divisions  are  ten  in  number,  and  occupy  the  same 


INTERCHANGEABLE  MANUFACTURING.         271 

space  as  nine  divisions  on  the  thimble.  Accordingly,  when  a 
line  on  the  thimble  coincides  with  the  first  line  of  the  veriner, 
the  next  two  lines  to  the  right  differ  from  each  other  one-tenth  of 
the  length  of  a  division  on  the  thimble ;  the  next  two  lines  differ 
by  two-tenths,  etc.  Note  the  left  hand  cut  of  graduations  on  the 
barrel  and  thimble  in  Fig.  296. 

When  the  caliper  is  opened,  the  thimble  is  turned  to  the  left, 
and  when  a  division  passes  a  fixed  point  on  the  barrel,  it  shows 
the  caliper  has  been  opened  one-thousandth  of  an  inch.  Hence, 
when  the  thimble  is  turned  so  that  a  line  on  the  thimble  coin- 
cides with  the  second  line  (end  of  first  division)  of  the  veriner, 
the  thimble  has  moved  one-tenth  of  one-thousandth,  or  one  ten- 
thousandth  of  an  inch.  When  a  line  on  the  thimble  coincides 
with  the  third  line  (end  of  second  division)  on  the  veriner,  the 
caliper  has  been  opened  two  ten-thousandths  of  an  inch,  etc. 
Note  the  right  hand  cut  of  graduations,  where  the  line  on  the 
thimble  coincides  with  the  fourth  line  (end  of  third  division) 
and  the  reading  is  three  one-thousandths  of  an  inch. 

To  read  the  caliper,  note  the  thousandths  as  usual,  then  count 
the  number  of  divisions  on  the  veriner,  commencing  at  the  left, 
until  a  line  is  reached  with  which  a  line  on  the  thimble  coincides. 
If  the  second  line,  add  one  ten -thousandth,  if  the  third,  two  ten- 
thousandths,  etc. 

SPECIAL   USES   OF    MICEOMETEE-OALIPEES. 

Besides  the  uses  for  which  the  micrometer  was  primarily  de- 
signed and  is  generally  used,  there  are  any  number  of  special 
uses  to  which  the  caliper  can  be  put :  In  the  following  I  enu- 
merate and  describe  a  number  which  will  no  doubt  be  the  means 
of  suggesting  many  others. 

In  order  to  determine  whether  the  dead  centre  and  the  live 
centre  of  a  lathe  are  in  line :  First,  set  the  centres  as  near  as  pos- 
sible by  eye ;  then  carefully  centre  a  piece  of  stock  about  six 
inches  long;  place  it  on  the  centre  and  turn  one  end  for  a  dis- 
tance of  about  one-half  inch,  using  a  sharp -edged  tool  so  as  to 
get  a  sm  ooth  surface.  Then  reverse  the  stock  so  that  the  turned 
end  will  be  at  the  live  centre.    Next,  turn  the  other  end  to  ex- 


272 


TOOL-MAKING   AND 


actly  the  same  diameter,  using  the  micrometer  to  gauge  it.  IsTow 
clamp  the  micrometer  to  the  cross-slide  of  the  lathe,  so  that  the 
end  of  the  barrel  or  ratchet-stop  will  rest  against  the  work,  as 
shown  in  Fig.  297.     You  can  now  set  your  centres  accurately  by 


Fig.  297. 

running  the  barrel  out  against  the  nearest  end,  noting  the  read- 
ing and  running  back  the  barrel,  running  the  carriage  up  to  the 
other  end  and  repeating  the  operation.  A  few  trials  and  adjust- 
ments of  the  tail-centre  and  both  centres  will  be  set  dead  in  line. 
In  order  to  test  the  lathe  to  see  whether  the  centres  are  the 
same  height  from  the  ways,  the  same  method  can  be  adopted  by 


Shcft 


Fig.  298. 

using  the  micrometer  backward,  from  the  top  down,  or  from  the 
bottom  up,  as  shown  in  Fig.  298. 

To  line  up  the  centres  on  a  grinder  so  as  to  get  them  dead  in 
line  the  micrometer  can  be  used  by  fastening  the  caliper  between 
the  collars  of  the  spindle  where  the  emery-wheel  is  usually  located, 
in  the  manner  shown  in  Fig.  299,  and  by  blocking  up  the  spin- 


INTERCHANGEABLE  MANUFACTURING. 


273 


die  in  the  most  convenient  manner.  In  using  the  micrometer  in 
this  manner,  however,  always  remember  that  all  round  or  circu- 
lar work  will  have  an  error  twice  that  evidenced  by  the  gauge. 


Jfimeri/  Jfflteet 


FIG.  299. 


That  is  to  say,  if  the  centres  show  only  0. 0012  by  the  microm- 
eter in  the  test,  they  will  shown  an  error  of  0.0024  on  the 
work.  On  straight  surface  work  the  test  will  show  the  actual 
error* 

It  will  be  at  once  obvious  to  the  practical  reader  that  this  sys- 
tem of  testing  can  be  applied  to  almost  any  machine  in  the  shop. 
On  the  planer,  miller,  shaper,  or  precision-lathe  it  will  be  found 
all  that  can  be  desired  in  detecting  errors  in  the  platen,  vise,  or 
fixtures;  while  when  utilized  in  the  lining  up  of  a  job  with  a 
finished  surface,  it  is  as  good  as  a  surface-tester  and  lends  itself 
much  more  readily  to  the  work  in  hand. 
In  fact,  this  system  can  be  almost  uni- 
versally applied  where  accurate  work 
from  machines  is  absolutely  required. 

The  micrometer-caliper  can  also  be 

used  as  an  inside  caliper  in  any  hole  in 

which  it  will  go  in  with  ease.     This  is 

shown  in  Fig.    300,    the  caliper  being 

used    to    gauge   the  inside   of  a  large 

cutting-die  when  grinding  it  to  the  finish  size.     To  use  the  gauge 

in  this  manner  it  is  only  necessary  for  one  to  learn  to  read  the 
18 


Fig.  300. 


274  TOOL-MAKING   AND 

graduations  backwards;  then  no  difficulty  will  be  experienced  in 
using  it  as  an  inside  micrometer. 

In  all  shops  where  micrometers  are  used  generally  it  will 
faciliate  their  use  and  expedite  the  production  of  accurate  work 
by  having  the  feed-screws  of  all  machines  fitted  with  graduated 
dials ;  and  if  the  micrometers  in  use  are  graduated  to  read  in 
thousandths,  by  having  the  dials  to  read  the  same. 

The  universal  use  of  micrometer-calipers  for  regular  machine- 
shop  gauges  is  not  far  distant,  as  it  will  not  be  long  before  the 
chief  and  perhaps  the  only  interdiction  to  their  extensive  use — 
their  cost — will  be  overcome.  That  the  demand  is  growing  is 
evidenced  by  the  fact  that  one  concern  in  the  East  manufactures 
a  line  measuring  from  six  to  twelve  inches  for  use  on  the  larger 
classes  of  interchangeable  machine  work. 

THE   HEIGHT-GAUGE   AND    ITS   USE. 

While  the  micrometer  occupies  first  place  among  the  small 
precision  tools  of  the  universal  shop,  there  is  another  tool  which 
follows  it  a  close  second.  I  refer  to  the  height  gauge,  Fig.  301 ; 
a  tool  that  although  it  is  used  quite  generally  among  tool-maskers, 
is  comparatively  unknown  outside  of  them.  If  more  wrere  known 
of  the  great  utility  of  this  handy,  accurate,  reliable,  and  almost 
indispensable  tool,  its  use  would  become  common  in  all  shops 
where  accurate  work  is  done.  By  many  the  height-gauge  is 
thought  to  be  merely  an  accessary  to  the  tool-maker's  kit,  and  of 
no  use  except  in  verifying  measurements ;  when,  on  the  contrary, 
it  can  be  used  for  a  thousand  and  one  jobs  in  the  attainment  of 
results  with  ease  which  would  otherwise  be  almost  impossible  of 
attainment  were  other  means  used.  In  accurate  work,  especially, 
by  means  of  the  height-gauge,  jobs  that  appear  to  present  insur- 
mountable difficulties  are  accomplished  with  ease. 

In  order  that  the  utility  and  value  of  this  accurate  tool  may 
become  better  understood  I  will  present  a  few  examples  of  its  use : 

By  far  the  most  usual  and  common  method  of  striking  or 
scribing  a  line  on  a  piece  of  work  is  with  the  surface-gauge ;  set- 
ting the  scriber  to  some  graduation  on  a  scale.  This  method, 
however,  is  not  to  be  compared  with  the  height-gauge  and  its 


INTERCHANGEABLE  MANUFA CTURING. 


275 


scriber  in  point  of  economy  of  time,  labor,  and  worry ;  for  the 
reason  that  the  height-gauge  may  be  set  almost  instantly  and  ac- 
curately when  one  is  familiar  with  it,  and  a  line  may  be  scribed 
with  it  at  once  with  the  assurance  positive  that  it  is  in  exactly  the 
place  that  one  wishes  it  to  be.  With  the  surface-gauge  the 
scriber  must  be  raised  and  lowered  many  times  before  the  cor- 
rect (?)  height  is  obtained ;  even  then  the  final  setting  is  a  guess. 


*t-= 


Fig.  301. 

For  example  second,  let  us  say  that  it  is  necessary  to  locate 
eight  holes  in  a  circular  finished  casting  as  per  Fig.  303 ;  the 
holes  to  form  the  corners  of  two  squares,  one  within  the  other, 
with  the  four  holes  of  each  equidistant  from  the  centre  of  the 
casting.  The  way  to  accomplish  the  desired  results  accurately 
with  ease  will  be  to  take  an  angle-plate  like  302,  true  it  on  three 
of  its  sides,  and  then  clamp  the  disk  on  its  face  A.  The  exact 
diameter  of  the  casting  in  which  the  holes  are  to  be  located  is 
found  first ;  then  the  height  of  its  lower  edge  from  the  surface- 
plate  on  which  the  angle-plate  rests;  then,   by  means  of  the 


276 


TOOL-MAKING  AND 


veriner  on  the  height-gauge  and  the  scriber  which  comes  with  it, 
we  scribe  two  lines  the  required  distance  apart,  equally  above 


Fig.  302. 


and  below  the  centre,  for  the  outside  square,  then  two  more  lines 
for  the  inside  square.     Next,  without  removing  the  casting  from 


Centers 


Centers 


Centers 


Center** 


Fig.  303. 


the  angle-plate,  we  turn  the  plate  on  to  face  B  and  then  scribe 
four  lines  in  a  like  manner,  thus  finishing  the  two  squares.     All 


INTERCHANGEABLE  MANUFA CTUBING. 


277 


is  now  ready  to  drill  and  tap  the  eight  holes  approximately  cor- 
rect, where  the  lines  intersect,  for  the  "button"  screws,  which 
we  use  to  locate  the  "buttons"  true  for  boring  the  holes.  From 
this  example  it  will  be  at  once  obvious  that  holes  may  be  located 
in  a  like  manner  on  any  given  surface,  providing  that  care  has 
been  previously  taken  to  have  the  surfaces  from  which  the  neces- 
sary measurements  are  taken  perfectly  true  and  square  with  each 
other. 

For  the  third  example,  we  will  take  the  block  shown  in  Fig. 
304,  which  has  a  hole  at  G  and  in  which  it  is  desired  to  drill  two- 
more  holes  centrally  with  the  first  one  way,  but  at  angles  with 
it  the  other,  as  shown  by  the  dotted  lines.  We  first  bolt  the 
angle-plate  on  the  table  of  the  miller,  square  with  the  sp indie, 


.Aticfular  Tfo/es 


..    .     .....           _  v 

*,i 

ii  \   / 

V 

, — T 

1 

FIG.  304. 


and  then  fasten  the  block  to  the  angle-plate,  at  the  required 
angle  with  the  table.  We  locate  a  plug  in  the  hole  first  drilled 
at  C,  as  shown  in  Fig.  305,  and  then  find  with  the  height-gauge 
the  exact  distance  the  centre  of  the  hole  is  from  the  table.  Then, 
with  a  plug  in  the  miller-spindle — which  must  run  perfectly  true 
— we  measure  from  the  plug  to  the  table,  raise  or  lower  the  knee 
until  the  centre  of  the  spindle  is  the  same  distance  from  the 
table  that  the  centre  of  the  plug  in  hole  G  is,  setting  it  horizon- 
tally, by  measuring  from  the  plug  in  the  spindle  to  the  angle- 
plate,  or  the  edge  of  the  block  to  be  drilled,  with  the  height - 
gauge.  We  have  now  everything  ready  to  bore  one  of  the  angu- 
lar holes ;  which  may  be  accomplished  by  using  a  draw-in  collet 
end-mill,  or  a  single-pointed  boring-tool,  to  finish  the  hole.  The 
other  hole  may  then  be  finished  in  the  same  manner  by  reversing 
the  block  on  the  angle -plate  and  proceeding  as  before. 


278 


TOOL-MAKING 


In  conclusion  I  may  state  that  experience  has  proved  that 
more  accurate  and  expeditious  results  can  be  obtained  with  the 
height-gauge  than  the  surface-gauge.  Lay  out  your  work  with 
the  height-gauge ;  prickpunch  carefully  where  the  lines  intersect 


Cfncfle  Plata 


Miller  Platen 


FIG.  305. 


— using  a  glass  where  unusual  "accuracy  is  essential — and  indicate 
carefully  on  the  lathe  face-plate ;  drill  the  hole,  and  finish  it  by 
boring.  In  this  manner  you  will  get  as  near  perfect  accuracy  as 
it  is  possible  to  get. 

If  you  are  machinist,  tool-maker,  or  die-maker,  learn  of  the 
multiple  uses  of  the  micrometer -caliper  and  the  height-gauge ; 
and  your  ability  to  do  fine  and  accurate  work  will  be  further  de- 
veloped and  your  earning  capacity  will  be  increased.  If  you  are 
a  shop  manager,  superintendent,  or  foreman,  furnish  your  de- 
partments and  tool-rooms  with  such  tools  and  teach  your  men 
how  to  use  them ;  as  by  so  doing  your  shop  will  produce  more 
and  better  work  accurately  with  ease. 


CHAPTER  XX. 

Mould  Construction. 
MOULDS. 

As  not  infrequently  the  making  of  moulds  form  part  of  the 
tool-maker's  work  it  will  be  well  to  devote  a  chapter  in  this  book 
to  this  interesting  branch  of  his  art. 

Moulds  are  used  to-day  for  the  production  of  a  variety  of  arti- 
cles too  numerous  to  mention.  Rubber  goods,  soft  metal  ware, 
.composition  goods,  glassware,  china,  and  a  thousand  and  one 
other  things  that  form  an  integral  part  of  our  twentieth  century 
civilization,  are  produced  in  moulds  made  by  our  most  skilled 
tool-makers.  Let  no  one  think  that  moulds  require  but  little  skill 
to  construct ;  for  if  they  do  they  will  find  themselves  greatly  mis- 
taken. In  order  to  construct  moulds  successfully  the  mechanic 
must  be  skillful  and  accurate.  In  order  that  the  articles  pro- 
duced in  them  shall  be  as  desired,  and  exact  duplicates  of  each 
other,  the  moulds  must  be  of  the  most  accurate  construction.  In 
fact  an  accurate  mould  must  be  constructed  in  much  the  same 
manner  as  an  accurate  drilling-jig  would  be,  as  its  products  are 
usually  of  the  interchangeable  class. 

In  order  that  the  tool-maker  may  be  assisted  in  deciding  upon 
the  proper  type  of  mould  to  adopt  for  the  production  of  an  arti- 
cle of  a  given  shape,  size,  aud  form  from  a  given  material,  I 
shall  illustrate  and  describe  in  the  following  pages  a  number  of 
sets  of  moulds  of  the  most  approved  construction.  The  descrip- 
tions will  also  point  out  the  way  to  construct  them  properly. 

MOULDS    FOE   PENCIL   CRAYONS. 

Fig.  306  shows  a  face  view  of  a  mould  for  pencil  crayons. 
As  will  be  seen,  it  was  made  in  two  parts  and  produced  twelve 
crayons  at  once.     Two  castings  A  and  B,  6  inches  wide  by  7 

279 


280 


TOOL-MAKING   AND 


inches  long,  with  lugs  on  one  end  of  each  for  the  hinge  portions, 
were  planed  all  over,  with  care  to  get  as  smooth  and  true  surface 
as  possible.  The  castings  were  very  close-grained  and  totally 
free  from  blow -holes.     After  they  were  planed  they  were  scraped 


LE 


K      u 


f\f\f\f\f\f]f\f\f\  f\f\f\ 


a 


f\f\f\f\f\f\f\f\f\f\f\f\ 


? 


F 


WWWWWWV_VWV_7WWW 


'UUUUUUU 


FIG.  306. 

on  the  sides  on  which  the  moulds  were  to  be,  until  they  were  as 
near  true  as  it  was  possible  to  get  them.  The  lugs  of  the  hinges 
were  then  machined  so  that  A  fitted  within  B  snugly.  The 
halves  were  then  clamped  together  and  the  holes  drilled  and 
reamed  through  the  lugs  for  the  pins  D,  which  were  driven  in. 
The  plates  A  and  B  were  then  held  In  the  vise  and  milled  through 
one  side,  leaving  a  rib  on  the  side  of  each,  as  shown  at  C  C,  and 
a  depression  R  between  them.  While  they  were  still  clamped 
together  the  centres  for  the  twelve  moulds  were  laid  out  and 
prickpunched. 

Next  the  pins  D  D  were  removed  and  the  plates  separated. 
We  now  have  a  centre  mark  on  the  face  of  each  plate  for  each 
of  the  twelve  moulds.  The  plate  A  was  then  strapped  on  the 
table  of  the  miller,  dead  square,  and  a  line  was  struck  from  each 


Fig.  307.— The  Reamer. 

centre  across  the  plate.  A  convex  cutter,  of  T1g--inch  radius,  was 
then  used,  and,  starting  at  the  mark,  was  run  along  the  line  on 
the  face  to  within  ^-inch  of  what  was  to  be  the  total  depth  of  the 
mould.  This  was  done  on  all  of  the  twelve  centres,  and  the 
other  plate  was  milled  likewise,  so  that  when  the  pins  D  D  were 


INTERCHANGEABLE  MANUFACTURING.         281 

inserted  and  the  plates  closed  and  clamped  together  there  were 
twelve  holes,  ^-inch  in  diameter,  straight  through  the  centre  of 
them,  or  a  half  of  a  ^-inch  circle  in  each  plate. 

The  plates  were  then  stood  with  the  side  c  c  np,  and  a 
drill  -Jj  of  an  inch  under  the  final  size,  and  extra  long,  was  run 
down  through  each  of  the  ^-inch  holes  to  within  f  -inch  of  the 
bottom,  the  ^-inch  hole  in  each  keeping  the  drill  perfectly  cen- 
tral. A  special  reamer,  of  the  shape  shown  in  Fig.  307,  was  then 
made  and  fed  down  into  the  hole  left  by  the  drill,  and  by  feeding 
down  very  slowly  a  smooth  round  hole  was  made  with  the  shape 
of  the  point  in  the  bottom.  All  the  twelve  holes  were  gone  over 
several  times,  until  the  exact  depth  was  reached  in  each.  The 
mould  was  then  opened,  and  all  the  dirt  and  chips  were  cleaned 
out.  It  was  then  closed  and  reclamped.  Several  pieces  of 
T3¥-inch  drill-rod  which  had  been  roughed  all  over  were  inserted 
■ — one  in  each  of  several  holes — and  melted  lead  poured  around 
them.  When  they  were  cold  the  mould  was  opened  and  the  lead 
forms  were  withdrawn,  thereby  furnishing  several  good  laps. 
The  laps  were  run  at  a  high  speed  iu  the  drill-press,  using  a  gen- 
erous amount  of  oil  and  emery,  and  the  holes,  or  moulds,  were 
lapped  and  polished  to  a  nice,  smooth  finish.  The  plates  were 
then  opened,  and  after  being  well  cleaned  with  benzine  there 
were  seen  twelve  perfect  semicircular  grooves  of  the  size  re- 
quired in  each  plate,  with  dead-sharp  edges  that  would  leave  no 
fins  on  the  work.  The  pins  D  D  were  then  eased  a  little,  so  that 
the  mould  could  be  opened  without  difficulty. 

The  next  thing  to  be  done  was  to  make  the  latch  F,  shown  in 
Fig.  308.     This  was  made  of  ^-inch  flat  steel  and  fastened  to 

J 


OOOOOOOOOOQQ;: 

'Wirt'ili1 


Fig.  308. 


the  plate  A  by  a  shoulder- screw.  A  small  stud  was  let  into  jP, 
for  a  handle  H.  The  spring  Q,  of  stiff  spring  steel,  was  made 
and  fastened  so  as  to  keep  a  strong  tension  on  the  latch  F.  The 
lock-pin  E  was  then  made  and  hardened  and  inserted  in  the 


282 


TOOL-MAKING  AND 


plate  B  so  that,  in  order  to  hold  the  two  halves  of  the  mould 
fast  and  snug,  the  half  B  was  brought  down  sharply  on  to  A, 
and  the  pin  E  striking  the  latch  F  it  was  forced  back  until  it 
snapped  over  the  pin,  thereby  locking  it.  This  j>roved  a  simple 
and  reliable  latch  and  was  quick  to  manipulate.  The  swinging 
plate  J  for  closing  the  channel  B  was  then  made  of  flat,  cold- 
rolled  steel  and  worked  out  and  finished  to  the  shape  shown, 
with  a  small  handle  at  K  and  swinging  on  the  screw  L.  The 
stop -pin  M  was  let  into  A  and  filed  off  so  that  the  plate  would 
swing  over  and  rest  on  it,  thereby  closing  the  channel  and  pre- 
venting the  liquid  material  from  running  out.     The  other  end 


Balancing 

Frame    v^tA 


FIG.  309. 


Fig.  310. 


Fig.  311.— Butt  Mill. 


was  closed  likewise,  and  the  mould  was  then  complete.  It  pro- 
duced nice,  smooth  crayons  without  the  trace  of  a  fin  or  a  lump 
on  the  entire  surface.  A  slight  shrinkage  which  resulted  in 
them  after  they  became  hard,  allowed  of  their  easy  removal  from 
the  moulds. 


MOULDS   FOE   LEAD   BALLS. 

In  Figs.  312,  313,  and  314  is  shown  a  mould  for  casting  a  lead 
ball  on  to  a  sheet-brass  frame,  as  shown  at  Fig.  309.  This  device 
was  used  as  part  of  a  balancing  mechanism,  and  it  was  necessary 
to  have  the  balls  all  exactly  the  same  weight  and  size,  and  in  the 
same  position  on  the  frame.  The  mould  used  is  shown  in  three 
views.  Fig.  312  shows  an  inside  view  of  each  of  the  two  sides ;  Fig. 
313  shows  the  bottom,  and  Fig.  314  the  top.  The  two  halves  of  the 
mould  were  castings,  and  were  machined  all  over  to  the  same 
size,  with  one  dead-smooth  side.  After  being  scraped  in  order 
to  true  them,  one  of  them  was  held  in  the  milling-vise,  taking 
care  to  have  the  vise  true  and  the  work  down  solid.  Then  the 
butt-mill  shown  in  Fig.  311  was  held  in  the  small  chuck  and  the 
table  moved  until  the  mill,  while  running,  just  touched  the  end 
of  the  casting  at  C :  the  table  was  then  moved  outward  and  along 


INTER  CHANGE  A  BLE  MANUFA  CT  VBING. 


283 


a  certain  number  of  thousandths  of  an  inch  (and  a  memorandum 
made  of  it)  for  the  first  hole  of  the  mould.  Care  had  been  taken 
to  finish  the  butt-mill  to  a  perfect  half-circle  of  the  radius  re- 


I 

J 

MM 

L        O 

Q 

o  o 

o 

o 

o 

o 

o 

0 

0 

o 

0 

o 

o 

0 

b 

9'  '0 

O 

IqJ     l 

9©~c 

fO( 

H 

K 

^oF 

foV 

,H. 

K 

)ov 

"°w, 

«««m 

^@" 

L 

Fig.  312. 


quired.  The  work  was  then  fed  against  it  and  the  mill  let  in  the 
required  number  of  thousandths,  or  to  the  depth  of  exactly  half 
the  diameter  of  the  mill.     The  screw-dial  graduation  was  then 


Fig.  313. 


noted,  and  the  work  brought  back  and  moved  along  for  the  next 
hole,  and  so  on  until  the  twenty -one  halves  were  finished. 

The  other  side  I)  was  then  held  in  the  same  manner,  the  mill 
set  and  fed  in  the  same  number  of  thousandths  as  before  and 


rrn 


G 

rnp, 


!  C 


c  i  rn 


G — e — £±k — e- 


-s — e — q — 0 — e — e — e — e — e — e-K-s-~e — e — e — o- 


m- 


Fig.  314. 

then  each  one  milled  to  the  same  depth  as  the  others.  After  this 
was  done  the  halves  were  removed,  and  two  brass  balls  were 
turned  up  and  finished  to  exactly  the  same  diameter  as  the 
moulds,  and  one  inserted  in  the  last  hole  in  each  end  of  the  plate 
C.  The  other  plate  I)  was  then  placed  on  the  top,  thereby  locat- 
ing the  half-moulds  perfectly  true  with  each  other.  A  hole  was 
then  drilled  at  each  end  and  reamed  for  the  dowel-pins  FF which 
were  made  and  driven  into  C.     The  holes  in  D  were  eased  so 


284  TOOL-MAKING  AND 

that  D  would  go  on  the  pins  nicely.  This  proved  a  simple  way 
of  locating  the  molds  exactly  true  with  each  other.  The  holes 
for  the  cap-screws  G  G  were  then  drilled  and  the  two  sides  G  D 
held  fast  together.  A  cutter  just  the  thickness  of  the  stock  used 
for  the  frames  was  then  run  straight  through  at  L  where  the 
two  pieces  C  D  lay  together,  to  the  depth  shown.  G  and  D  were 
then  separated,  and  the  centres  laid  out  for  the  holes  opposite 
each  mould,  as  shown  at  1 1.  The  holes  were  then  drilled  about 
£-inch  deep,  and  reamed  to  allow  the  pins  to  be  driven  in  to  hold 
the  frames  in  place,  as  shown  in  the  upper  right-hand  mould. 
Each  of  the  sides  was  then  set  up  in  the  shaper  and  a  tool  just 
the  width  of  the  frame  at  B  centred  with  the  holes  i"  I  opposite 
each.mould,  and  a  channel  planed  into  the  centre  of  each  mould, 
as  shown  at  J,  to  the  same  depth  as  L.  The  idea  and  form  are 
shown  clearly  in  Fig.  312.  The  parts  C  and  G  were  then  put  to- 
gether and  the  screw  G  tightened  and  the  holes  drilled  through 
which  the  lead  was  to  run  into  the  moulds,  as  shown  at  H,  using 
a  No.  40  drill  and  running  into  the  centre  of  each  mould,  leav- 
ing half  a  hole  in  each.  The  sides  G  and  D — still  together — were 
then  held  in  the  miller-vise,  and  an  angular  cutter  was  used  to 
mill  a  trough  for  the  metal  at  K  to  the  length  and  width  shown, 
and,  for  depth,  to  within  ¥3¥ -inch  of  the  moulds,  leaving  the 
small  channels  as  shown.  The  two  sides  were  then  separated  and 
the  faces  polished  with '  fine  emery-cloth  and  all  the  burrs  re- 
moved, being  careful  to  leave  the  edges  of  the  moulds  sharp. 
The  small  pins  were  made  and  driven  in  to  the  holes  1  and  then 
filed  down  to  just  the  thickness  of  the  frames,  and  the  tops 
slightly  rounded.  A  frame  was  then  entered  on  to  each  of  the 
pins,  as  shown  at  M,  thereby  holding  them  all  central,  the  chan- 
nels J  keeping  them  steady.  The  two  sides  were  then  put  to- 
gether, and  the  mould  being  complete,  it  was  held  in  the  vise. 
The  lead  was  heated  to  run  freely,  poured  into  the  trough  K  and 
running  through  the  small  holes  H  into  the  mould.  After  the 
metal  had  set,  the  screws  were  loosened,  D  lifted  off,  the  cast- 
ing removed,  and  the  balls  chipped  off  at  the  small  neck  caused 
by  the  holes  H,  leaving  twenty- one  balancing  frames  with  a  per- 
fect half  at  the  end  of  each,  all  exactly  the  same.  The  one  thing 
necessary  in  making  a  mould  of  this  kind  is  a  perfect  mill  and 


INTERCHANGEABLE  MANUFACTURING. 


285 


accurate  spacing,  and  the  work  resulting  will  show  no  fin.  The 
machine  used  was  a  Cincinnati  universal,  and  it  was  surprising 
how  dead  accurate  the  spacing  was,  there  not  being  a  difference 
in  any  of  the  work  produced,  either  in  size  or  shape. 


MAKING  MOULDS  FOR  TELEPHOKE-RECEIVER 
PIECES. 

The  moulds  here  shown  in  Figs.  315,  316,  and  317  are  of  a 
type  used  in  manufacturing  imitation  rubber  or  composition 
goods  for  various  purposes,  such  as  syringes,  bicycle  handles  and 


Fig.  315. 


Fig.  316. 


Fig.  317. 


Fig.  318.— The  Piece 
to  be  Made. 


Fig.  319. 


parts  of  the  telephone.  The  moulds  were  used  for  moulding  the 
receiver  case  from  a  composition  which,  when  hard,  closely  re- 
sembles rubber,  and  is  known  as  electrose.  Moulds  of  this  con- 
struction are  used  in  the  hydraulic  press,  and  the  composition  is 


286 


TOOL-MAKING  AND 


in  a  liquid  form  when  pressed  into  the  mould.  The  article  pro- 
duced is  shown  in  a  cross-section  in  Fig.  318.  The  top  or  face 
is  concave  and  the  edges  are  rounded.  The  case  is  thin  at  the 
centre  and  heavier  at  the  outside,  terminating  in  a  square  shoul- 
der and  a  thread  of  18-pitch.  There  is  a  -§  -inch  hole  through 
the  centre. 

For  the  mould,  pieces  of  flat  soft  steel  were  planed,  clamped 
with  the  smooth  sides  together,  and  a  hole  E  at  each  end  drilled 
and  reamed  for  dowel-pins.  The  pins  were  forced  tightly  into 
the  lower  plate  and  projecting  properly  into  the  upper  plate. 


f^L 


Fig.  320. 


Fig.  321. 


Fig.  322. 


The  sides  and  ends  of  the  plates  were  then  squared  together  in 
the  miller,  and  the  twelve  holes  A  were  drilled  through  both  sec- 
tions and  reamed  to  finish  size.  A  pair  of  templets  of  the  inside 
and  outside  shape  of  the  article  were  filed  out  and  then  special 
counterbores,  finishing -tools,  and  the  tap  were  made.  The  first 
tool,  Fig.  319,  was  for  the  too  of  the  case  in  the  upper  section, 
and,  Fig.  320,  was  for  the  face  of  the  core  F  in  the  lower  section. 
N  is  the  forming-  and  cutting-edge  and  the  hole  0  fits  the  stem  of 
the  core.  The  straight  face  counterbore  Q,  Fig.  321,  finishes  the 
twelve  moulds  in  the  lower  plates,  leaving  them  square  at  the 
bottom  and  sizing  them  for  the  tap.  This  tap,  Fig.  322,  as  well 
as  the  three  counterbores,  had  a  central  or  guide-pin  fitting  for 
the  reamed  holes. 

The  upper  plate  was  clamped  (not  too  tightly)  to  the  drill- 
press  table,  with  one  of  the  holes  A  directly  under  the  stem  en- 
tered the  hole  T,  as  shown  in  the  cross-section  of  the  plate.     The 


INTERCHANGEABLE  MANUFACTURING.         287 

counterbore  was  then  fed  clown  iuto  the  plate  to  the  proper  depth, 
and  all  the  twelve  holes  were  finished  in  this  manner,  which  com- 
pleted the  upper  plate,  except  the  lapping. 

The  first  counterboring  of  the  lower  plate  was  accomplished 
in  the  same  manner  by  the  fiat-faced  counterbore,  Fig.  321.  The 
next  operation  was  to  tap  the  holes,  which  was  done  in  the  same 
drill-press,  running  very  slowly  and  using  plenty  of  soap-water 
as  a  help  iu  cutting,  and  by  careful  work,  and  by  running  the 
tap  in  and  out  a  few  times,  a  sharp,  smooth  thread  was  secured. 
The  numerous  flirtings  of  the  tap,  Fig.  322,  worked  admirably. 
There  was  also  very  little  lead  to  the  tap,  as  we  wished  the  first 
thread  in  the  finished  case  to  be  as  full  as  possible. 

The  cores  were  then  made  of  machine  steel,  first  cut  into 
lengths  for  two.  These  pieces  were  first  turned  at  both  ends  to 
form  the  stems  D  to  be  driven  tightly  into  the  hole  A.  The  pieces 
were  then  cut  in  two  and  held  by  the  stem  in  a  nose -chuck  that 
ran  perfectly  true,  when  the  stud  at  the  opposite  end  was  fin- 
ished to  fit  nicely  in  the  holes  A  in  the  upper  plate.  After  this 
was  done  to  all  of  them,  the  facing-  or  forming-mill,  Fig.  320,  was 
used  for  the  face  of  the  cores.  The  cores  being  held  by  the  stem 
D  in  the  nose-chuck,  the  centre  in  the  end  of  the  shank  of  the 
facing-mill  was  placed  on  the  tail-centre  and  the  short  stem, 
turned  on  the  face  of  the  core,  entered  the  hole  0  in  the  facing- 
mill,  which  was  then  fed  in  until  the  shape  and  size  desired  was 
produced  on  the  face  of  the  core.  The  twelve  cores  were  then 
highly  polished  and  driven  tightly  into  the  hole  A  in  the  lower 
plate.  All  burrs  thrown  upon  the  face  of  the  plate  by  the  tools 
used  were  then  removed,  leaving  a  sharp  edge  to  each  of  the 
moulds. ' 

There  then  remained  to  finish  the  moulds  the  lapping  and 
polishing  of  the  upper  plate  which  formed  the  faces  or  tops,  and 
which  required  a  high  shining  polish  as  they  left  the  mould. 
We  made  a  few  lead  laps  by  pouring  lead  into  the  sections  B, 
casting  them  around  steel  stems,  which  in  use  projected  into  the 
holes  A,  and  then,  by  using  flour,  emery,  and  oil  and  running  the 
laps  as  fast  as  possible,  the  moulds  were  lapped  to  a  finish  and 
polish  that  was  very  nearly  perfect.  By  putting  the  two  plates 
together  it  was  seen  that  there  was  not  the  slightest  defect  in  the 


288  TOOL-MAKING   AND 

alignment  of  the  holes  A  in  both,  testing  them  as  we  did  with  a 
standard  plug-gauge.  One  side  of  each  of  the  plates  was  then 
marked  "Front"  to  avoid  mistakes. 

When  moulding  the  cases,  the  upper  plate  was  removed,  and 
the  composition  was  poured  over  the  face  of  the  lower  plate. 
The  upper  plate  was  then  replaced,  and  the  projecting  stems  of 
the  cores  F  in  the  lower  plate  entered  the  holes  A  in  the  upper 
plate,  thereby  preventing  the  liquid  from  squeezing  out  and  also 
forming  the  hole  J  in  the  finished  case.  The  two  plates  were 
then  placed  under  the  hydraulic  press  and  sufficient  pressure  was 
brought  down  on  them  to  press  the  fluid  into  every  portion  of 
the  moulds,  the  pressure  being  so  great  as  to  force  every  bit  of 
surplus  composition  from  between  the  sections.  This  composi- 
tion was  used  while  very  hot,  and  required  a  few  seconds  to  cool 
before  removing.  When  cooled,  the  upper  section  was  removed, 
and  the  slight  shrinkage  resulting  from  the  cooling  allowed  the 
finished  cases  to  be  removed  by  screwing  them  out  of  the  lower 
plate  by  hand.  When  thus  removed  they  had  a  fine,  smooth 
polish  on  all  the  outer  surfaces  and  a  good,  sharp,  smooth  thread. 

HOW   AN   ACCUEATE    SET   OF    MOULDS   WAS 
MACHINED   IN   THE  PLANEB. 

In  Fig.  323  are  two  views  of  the  finished  lower  section  of  a 
mould  used  for  moulding  square  sticks  of  crayons  with  one  end 
curved  and  tapered,  as  shown  in  Fig.  324.  There  were  ten  sets 
of  these  moulds  to  be  made,  and  as  we  were  getting  a  good  price 
for  them  we  were  glad  to  get  the  job.  Now,  as  will  at  once  be 
seen,  the  job  is  a  milling  job,  and  the  universal  milling-machine 
the  machine  to  do  it  in.  As  we  had  no  milling -machine,  how- 
ever (universal  or  otherwise),  we  had  to  look  around  for  other 
means. 

At  last  we  decided  that  they  could  be  finished  throughout  in 
the  planer  by  the  use  of  a  few  special  tools  and  attachments. 
Fig.  325  shows  how  the  sections  of  the  moulds  are  cored  out  at 
the  back  at  A  A,  leaving  a  rim  all  round  the  outside.  These 
sections,  or  plates,  were  of  cast-iron  of  very  close  grain.  The 
twenty  castings  for  the  ten  moulds  were  first  planed  on  the  top 


INTERCHANGEABLE  MANUFA CTURING. 


289 


and  bottom,  and  the  mould  face  of  each  scraped,  so  that  the  sec- 
tions would  surface  at  all  points.  The  sections  were  then  paired 
and  the  holes  B  B  drilled  and  reamed  through  them,  in  the 
positions  shown,  for  the  three  dowel-pins-  of  Stub  steel.     These 


THE  JOB  AS  FINISHED  IN  THE  PLANER. 


c      c 

c 

c 

c 

c 

B 

c 

c 

c 

c 

c     c 

!;';, 

r 

,,\ 

"  'S 

■wm 

CROSS  SECTIONAL  FRONT  VIEW. 

Fig.  323. 


pins  were  driven  tightly  into  one  section  of  each  of  the  ten 
moulds,  and  the  holes  in  the  other  sections  eased  up.  The  two 
sections  of  each  mould  were  then  numbered  and  the  moulds,  with 


Fig.  324.— The  Piece  Produced  in  the  Moulds. 


the  sections  clamped  together,  were  then  strapped  on  the  planer- 
bed  and  their  four  sides  planed  square  with  each  other  and  with 
the  mould  faces  of  the  section,  care  being  taken  to  finish  the  lot 


Fig.  325. 

of  ten  to  the  same  width  and  length.     We  were  now  ready  to 

finish  the  moulds  proper,  and  to  do  this  the  tools  and  fixtures 

shown  in  the  accompanying  illustrations  were  made. 

As  seen  in  Fig.  324,  the  crayons  produced  in  the  mould  were 

required  to  be  T^-inch  square,  with  one  end  tapered  and  curved 
19 


290 


TOOL-MAKING   AND 


to  a  1^-inch  radius.  They  were  to  be  finished  so  that  they  would 
present  a  smooth  surface  on  all  sides,  without  fins  and  with  the 
ends  tapering  symmetrically.  To  accomplish  this  result  in  the 
planer  it  was  necessary  to  provide  means  for  raising  the  form- 


FIG. 326. 

ing-tool  (for  finishing  the  moulds)  so  as  to  produce  the  shape 
desired.  The  first  thing  made  was  a  templet.  This  templet  was 
worked  out  with  one  square  side  to  work  from  and  then  finished 
to  a  1^-inch  radius.  It  was  used  to  finish  the  cam  shown  in  two 
views  in  Fig.  326  and  on  the 
planer-bed  in  Fig.  327.  This 
cam  was  of  cast-iron  with  ears 
at  each  end  to  admit  fastening- 
bolts,  and  with  the  cam  faces 
long  enough  to  take  in  the  entire 
length  of  mould  sections.  It  was 
first  planed  on  the  back  and  the 

CAM  FOR  RAISINQ  TOOL-HOLDER. 


FORMING  TOOL. 


METHOD  OF  FINISHING  THE  MOULDS  AND  DUPLICATING  THE  CURVER  TAPER  ENDS. 


FIG.  327. 

tongue  G  fitted  to  the  central  slot  in  the  planer-bed.  The  cam 
face  F  F  was  then  planed  up  and  finished  to  the  templet,  shown 
at  left  of  Fig.  326,  after  making  sure  that  it  was  at  right  angles 
with  the  sides  of  the  tongue  G.  The  front  side  of  the  casting  was 
also  squared  so  as  to  have  a  locating  side  for  the  mould  sections  to 


INTERCHANGEABLE  MANUFACTURING. 


291 


square  against.  Next  came  the  tool -holder.  This  was  got  out  of 
a  bar  of  1^-inch  square  mild  steel,  bending  and  drawing  down  one 
end  to  If  by  ■$,  to  the  shape  shown  in  the  front  and  side  views 
of  Figs.  327-330.  The  end  of  the  extension  at  N  A  was  milled 
through  with  a  §  -inch  cutter  to  admit  the  roller  0  of  machine 
steel,  which  was  finished  to  fit  the  slot  N  N  snugly,  and  to  If  inch 
in  diameter,  located  by  the  Tyinch  stud  P  to  revolve  freely  within 
the  holder.  A  f -inch  square  hole  was  worked  through  the  holder 
to  admit  the  forming-tool,  Fig.  331,  care  being  taken  to  get  it 
square  with  the  sides  of  the  roller  0.  A  hole  was  also  drilled  and 
tapped  to  admit  the  set-screw  Q  for  holding  the  forming-tool. 
This  tool,  Fig.  331,  was  of  f -inch  square  tool  steel,  finished  at  R 
to  a  y5¥-inch  right  angle,  terminating  in  a  square  surface  on  each 
side  at  S.  The  correct  shape  of  the  cutting  portion  was  carried 
back  to  the  full  thickness  of  the  tool,  giving  the  cutting-edge  the 
amount  of  clearance  shown.  This  completed  the  tools  necessary 
to  finish  the  moulds  in  themselves. 

Now,  as  will  be  seen  in  Fig.  323,  the  moulds  are  constructed 
to  produce  twelve  crayons,  and  it  is  necessary  to  space  the  twelve 
moulds  C  accurately,  so  that  those  in  both  sections  will  coincide 


INDEX  NOTCH. 


Fig.  328. 


with  each  other  perfectly  when  the  sections  are  fastened  together. 
To  do  this,  some  kind  of  an  indexing  device  was  necessary.  The 
use  of  the  notched  hand-wheel,  Fig.  328,  and  the  "flopper"  or 
index-pawl,  Fig.  329,  answered  for  this,  and  allowed  of  the  spac- 
ing of  the  moulds  being  acccomplished  with  rapidity  and  very  lit- 
tle trouble.  This  hand- wheel  was  fitted  to  key  on  to  the  horizon- 
tal feed-screw  of  the  planer  and  had  a  notch  cut  into  its  rim  in 
the  position  shown.     The  "flopper"  or  index-pawl  consists  of 


292 


TOOL-MAKING  AND 


s3 


Fig.  330. 


FORMING  TOOL. 


three  parts:  the  back-plate  I,  the  flopper  or  pawl  J,  finished  at 
K  to  fit  the  notch  in  the  hand-wheel,  and  the  shoulder-screw  L, 
for  fastening  the  parts  together.  This  completed  all  fixtures 
necessary  to  the  finishing  of  the  moulds. 

The  manner  of  finishing  the  sections  in  exact  duplication  of 
each  other  and  spacing  them  correctly  is  shown  in  Fig.  327. 
This  is  sufficiently  clear  to  be  understood  with  a 
short  description.  The  cam  for  raising  the  tool- 
holder  is  fastened  to  the  planer  by  bolts  at  either 
end.  The  section  of  the  mould  marked  "the  work" 
is  located  squarely  against  the  square  front  of  the 
cam;  lengthwise  and  sidewise  against  the  stop. 
It  is  then  clamped  securely  to  the  platen  of  the  bed. 
The  tool-holder  is  now  fastened  in  the  tool-post — the 
apron  of  which  has  first  been  set  perfectly  square 
with  the  planer-bed.  The  forming-tool  is  fastened 
within  the  holder — squaring  it  with  the  work  by 
means  of  the  parallel  edges  S  S  and  allowing  it  to 
project  out  of  the  holder  so  the  point  of  the  cutting- 
edge  is  T\-inch  below  the  face  of  the  roller,  as  in 
Fig.  327.  The  stroke  of  the  planer-bed  is  then  set, 
the  hand-wheel  fastened  on  the  feed-screw,  and  the 
"flopper"  clamped  so  that  the  end  K  will  enter  the 
notch  in  the  hand-wheel,  the  back-plate  of  the  "flopper"  being 
clamped  to  the  upright  side  of  the  planer. 

Everything  is  now  ready:  Starting  from  one  side  of  the 
mould-plate,  the  forming-tool  is  moved  over  by  revolving  the 
hand-wheel  a  given  number  of  times,  and  the  indexing-pawl  is 
dropped  into  the  notch.  The  planer  is  then  started  and  the  form- 
ing-tool is  gradually  raised,  thereby  finishing  and  cutting  the 
mould  at  this  end  in  exact  duplication  of  the  shape  of  the  cam 
face.  To  gauge  the  depth  of  the  moulds  the  tool  is  fed  down  un- 
til the  straight  edge  S  S  of  the  tool  touches  the  face  of  the  mould- 
plates.  When  the  first  mould  is  finished  the  tool  is  moved  over 
the  necessary  distance  by  revolving  the  hand-wheel  and  indexing 
in  the  notch,  and  the  operations  are  repeated  until  all  twelve  of 
the  moulds  in  the  section-plate  are  finished.  The  plate  is  then 
removed  and  another  set  up  in  the  same  manner  and  finished. 


y 


R       R 
FIG.  331. 


[NTERCHANGEABLE  MANUFA  CT URING. 


293 


The  twenty  sections  or  mould -plates  are  all  finished  in  this  man- 
ner, each  one  being  an  exact  duplicate  of  the  other,  and  all  coin- 
ciding perfectly  when  put  together. 

The  method  used  here  for  finishing  these  moulds  can  be 
adapted  for  a  large  variety  of  different  work,  as  will  be  at  once 
seen,  and  the  labor  and  expense  incurred  will  not  exceed  that 
called  into  play  if  the  work  was  done  in  the  milling-machine. 


MOULDS   FOE   BICYCLE  HANDLE-TIPS. 

In  Figs.  332  and  333  are  shown  plan  views  of  the  top  and 
bottom,  respectively,  of  a  set  of  moulds  for  the  moulding  of  com- 
position bicycle  handle-tips,  and  in  Fig.  336  a  cross-section  of 
the  mould  complete.  The  piece  produced  is  shown  in  Fig.  335 
and  the  drawn  and  perforated  tin  shell  which  forms  the  skele- 
ton of  the  work,  and  around  which  the  composition  material  is 


Fig. 332. 

moulded,  is  shown  in  Fig.  334.  The  perforations  in  the  shell  or 
ferrule  are  to  allow  of  the  composition  running  into  them  when 
the  tips  are  being  moulded.  The  moulds  shown  produce  four- 
teen tips  at  a  time,  and  as  the  construction  of  them  entails  con- 
siderable practical  knowledge  and  skill,  it  is  of  sufficient  interest 
to  describe. 

Two  mild-steel  plates  for  the  two  sections  A  and  B  of  the 
moulds  which  form  the  top  and  bottom  respectively,  were  first 
planed  all  over,  and  one  side  of  each  scraped  until  they  surfaced 


294 


TOOL-MAKING   AND 


■ — when  placed  together — at  all  points.  Both  plates  were  then 
clamped  together  and  holes  drilled  and  reamed  through  both  for 
the  three  taper  dowel-pins  C  C  C.     The  pins  were  then  got  out 


Fig.  333. 

and  driven  into  the  bottom  plate,  and  the  two  sections  placed  to- 
gether, and  a  cut  taken  off  all  four  sides  to  get  both  plates  dupli- 
cates of  each  other.  The  top  section  was  then  removed  from  the 
other  and  the  face  laid  out  for  the  fourteen  cores  C  in  the  rela- 
tive positions  shown  in  the  plan  views,  Holes  were  then  drilled 
N through  the  plate  at  these  points  and  reamed  to  size  (T7g-inch), 


./£ 


w 

.  G 


Tc 


M=='E     K E      v E     r E     V KE.„ 

\>       '. : -J 


FiCx.  331. 


Fig.  335. 


Fig.  336. 


and  then  countersunk  slightly  at  the  back.  The  two  sections 
were  then  reclamped  together,  the  three  dowels  C  C  C  locating 
them — and  the  holes  in  the  top  section  transferred  to  the  lower, 
drilling  into  a  depth  slightly  less  than  the  total  depth  to  which 
the  moulds  were  to  be  finished,  as  shown  at  E  in  the  cross-sec- 
tional views,  Fig.  336.  The  upper  section  was  now  removed  and 
the  holes  drilled  in  the  lower  section  counterbored  to  ^-inch  in 
depth,  arid  in  diameter  to  the  size  of  the  reamer,  Fig.  337.  The 
semicircular  channels  in  the  face  of  each  mould  at  F  were  then 


INTERCHANGEABLE  MANUFA  CT UBING. 


295 


let  in,  and  finished  by  using  the  tool  shown  in  Fig.  338,  the  end 
of  which,  at  H,  fitted  the  holes  reamed  by  the  reamer,  Fig.  337, 
snugly,  the  cutter  J  finishing  the  channels  to  the  required 
depth.  A  finishing,  reamer  of  the  exact  taper  and  size  required 
was  then  let  in,  finishing  the  moulds  to  the  shape  and  depth 
shown  in  Fig.  336,  the  upper  edges  or  largest  diameter  of  each 
just  meeting  the  inner  edges  of  the  semicircular  channel  F,  leav- 
ing a  sharp  edge  all  around.  The  moulds  were  then  lapped  to 
a  high  finish,  getting  all  marks  and  scratches  out  by  the  use  of 


Fig.  338. 


Fig.  339. 


the  copper  expansion  lap  shown  in  Fig.  339,  and  flour,  emery, 
and  oil.  The  lower  section  of  the  moulds  was  now  complete. 
To  finish  the  upper  section  there  remained  the  fourteen  cores,  as 
shown  in  the  plan  view,  Fig.  332,  and  in  the  cross-sectional  views, 
Fig.  336,  at  G.  These  cores  were  made  in  the  lathe,  and  were  of 
machine  steel,  first  cutting  off  pieces  of  sufficient  length  to  get 
out  two  cores,  and  then  centring  them  and  turning  down  each 
end  to  fit  tightly  the  reamed  holes  in  the  upper-section  plate. 
The  pieces  were  then  cut  in  two  and  held  in  a  nose -chuck  by  the 
finished  stems,  and  the  core  faces  turned  and  finished  to  the  re- 
quired shape  and  size  with  a  forming-tool — that  is,  to  just  fit  the 
inside  of  the  tin  ferrules,  Fig.  335.  The  stems  of  these  cores 
were  then  driven  into  the  holes  in  the  upper  sections,  shoulder- 
ing tightly  within  the  plate  as  shown  at  D.  The  mould  was  now 
complete  and  ready  for  work. 

One  of  the  perforated  tin  ferrules,  Fig.  335,  was  slipped  on 
to  each  of  the  cores  and  the  composition  to  be  moulded  spread 
into  the  moulds  E.  The  two  sections  were  then  located  together 
by  the  three  dowels  C  C  C,  and  the  mould  placed  under  the 


296  TOOL-MAKING  AND 

hydraulic  press  and  the  two  sections  forced  together,  which 
caused  the  composition  to  compress  to  the  limit,  with  the  surplus 
forced  out  from  each  mould  and  into  the  semicircular  channels 
in  the  face  of  the  sharp  edges  on  the  insides,  trimming  the  stuff 
from  that  within  the  moulds.  The  mould  was  now  removed  from 
the  press  and  the  sections  separated,  when,  by  rapping  the  lower 
section  and  the  back  with  a  mallet,  the  moulded  pieces  dropped 
but,  the  result  being  fourteen  highly  finished  tips  of  the  shape 
shown  in  Fig.  344.  The  perforated  tin  ferrules  on  the  inside  of 
the  tips  made  them  stroug  and  durable,  and  the  presence  of  the 
pierced  holes  L  around  the  shells  for  the  composition  to  run 
into,  eliminated  the  possibility  of  the  two  parts  separating,  or 
the  composition  loosening  or  chipping  off. 

MOULDS   FOR   "  POKER-CHIPS. " 

In  Fig.  340  is  shown  a  cross-section  view  of  a  mould  for 
poker-chips,  and  in  Fig.  341  a  plan  view  of  the  bottom  section. 
As  both  sections  of  this  mould  are  exact  duplicates  of  each 
other,  the  one  illustration  will  serve  for  both.     The  manner  of 

o  O 


R  "Q  "'"r     Q     "R  "ST    R"'   Q    "r:     ; 

t,.;...  '■..- ^ i_L 


FiG.  340. 

preparing  the  mild-steel  plates  for  the  sections  M  and  N,  Fig. 
340,  and  the  manner  of  locating  them  by  the  three  dowel-pins 
OOO  are  the  same  as  that  pursued  in  the  other.  As  can  be  seen 
in  the  plan  view  of  the  section-plate,  Fig.  341,  the  mould  had  a 
capacity  of  sixteen  chips.  The  manner  of  spacing  these  moulds 
and  finishing  to  coincide  with  each  other  is  as  follows :  The  two 
plates  after  being  doweled  together  are  planed  square  on  all 
sides;  one  side  of  each  then  marked  to  work  from,  choosing  op- 
posite sides.  One  of  the  sections  is  then  clamped  facing  the 
spindle  to  an  angle-plate  on  the  universal  milling-machine,  with 
the  marked  end  resting  squarely  on  the  miller-table.  The  form- 
ing-mill, Fig.  342,  is  then  held  in  the  miller-chuck,  and  the  table 


INTERCHANGEABLE  MANUFACTURING 


297 


raised  until  the  work  is  in  line  with  the  first  row  of  moulds. 
The  table  is  then  moved  along  until  the  cutter  will  just  touch  the 


FIG.  341. 


side  of  the  plate.  We  now  move  the  table  longitudinally  the 
exact  distance  required — by  noting  the  graduated  dial  on  the 
feed-screw — and  the  first  mould  is  finished  by  moving 
the  work  against  the  cutter ;  letting  it  in  the  number 
of  thousands  required.  The  work  is  then  backed  out 
and  the  table  moved  for  the  next  mould,  treating 
each  mould  of  the  first  line  in  the  same  manner  and 
getting  them  exactly  the  same  number  of  thousands 
apart.  When  the  first  row  is  finished,  the  table  is 
raised  the  same  distance  as  the  space  between  the 
first  row  of  holes,  then,  by  starting  from  the  same  side 
for  the  first  row,  the  second  row  of  holes  is  finished, 
and  so  on  until  all  are  complete.  The  one  thing  nec- 
essary is  the  accurate  spacing  and  sinking  of  the 
moulds,  being  sure  to  take  up  all  back  lash  in  the  feed- 
screws before  starting  the  divisions.  When  letting  in  the  forming- 
cutter,  a  generous  supply  of  oil  was  kept  running  on  the  cutter, 


Fig.  342. 


298 


TOOL-MAKING  AND 


the  cutting-edges  of  which  had  been  ground  and  oil-stoned  to 
take  smooth  polishing  cuts. 

The  finishing  of  the  other  sections  was  accomplished  in  the 
same  manner  as  the  first,  starting  from  the  marked  side  and 
working  from  it  as  in  the  other.  In  the  plan  view,  Fig.  341,  Q  Q 
are  the  moulds  and  B  B  the  semicircular  channels  for  the  surplus 
stock  to  run  into.  These  moulds  were  required  to  be  finished  so 
that  the  outer  edges  of  the  "  chips "  produced  would  be  about 
0.005  higher  than  the  centres,  this  being  necessary  in  order  for 
the  chips  to  "stack  "well  and  even.  The  moulds  were  lapped 
and  polished  smooth  by  means  of  a  lead-lap  in  the  drill-press, 
running  it  at  a  high  speed  in  order  to  get  a  high  finish  in  the 
moulds. 

SPHERICAL   MOULDS. 

Moulds  and  dies  for  spherical  forms  of  various  radii,  such  as 
globes  and  rings,  often  have  to  be  formed  in  the  lathe.  Such 
moulds  are  used  particularly  in  rubber  factories  for  balls  and 


FIG.  343. 


bicycle  tires,  and  the  little  tool  illustrated  in  Figs.  343  and  344 
was  designed  for  such  requirements,  as  it  was  found  rather  ex- 
pensive to  make  forming-tools  for  each  size  of  mould  that  had  to 
be  made.  The  fixture  was  designed  to  be  bolted  on  to  the  car- 
riage of  the  lathe  by  bolts  in  the  T-slot  of  the  tool-carrying  block, 


INTERCHANGEABLE  MANUFACTURING. 


299 


thus  giving  it  all  the  ordinary  movements  given  to  a  lathe-tool, 
with  the  additional  circular  ones. 

The  tool,  as  shown  in  the  drawing,  consists  of  the  cast-iron 
base,  having  a  tongue  which  fits  the  T-slot  of  the  tool-block,  and 
is  firmly  held  thereon  by  the  bolts  shown.  A  cap  is  fastened  to 
the  base  by  counterbored  screws,  while  projections  upon  it  and 
a  groove  in  the  base  serve  to  locate  the  cap.     The  worm-gear, 


Pig.  344. 

having  trunnions  integral  with  it,  is  journaled  in  the  extension 
or  wings  of  the  base  and  cap.  Meshing  with  the  worm-gear  is 
the  worm,  the  shaft  of  which  is  journaled  by  the  base  and  cap 
and  extends  toward  the  front  of  the  lathe,  where  it  terminates  in 
the  hand-wheel  at  a  convenient  length.  An  oblong  slot  is  cut 
in  the  worm-gear  to  receive  the  turning-tool,  which  is  fastened 
by  the  central  set -screw. 

As  moulds  and  dies  are  usually  made  in  halves,  it  is  not  often 
required  to  turn  out  more  than  this,  but  proper  proportioning  of 
the  fixture  allows  as  much,  as  two-thirds  of  the  sphere  to  be 
turned  out.  The  device,  of  course,  will  turn  out  moulds  for  cir- 
cular rings  as  well  as  for  balls  by  simply  setting  it  out  from  the 
line  of  centres  to  the  required  radius. 


CHAPTER  XXL 

Special  Tools,  Fixtures,  Devices,  Arrangements,  Con- 
trivances, and  Novel  Methods  for  Metal-Working. 

THE  DEVISING   AND   CONSTRUCTING   OF   SPECIAL 

TOOLS. 

While  the  constructing  of  the  regular  types  and  standard 
classes  of  tools  necessitates  skill,  accuracy,  judgment,  and  experi- 
ence on  the  part  of  the  tool-maker,  it  is  in  the  devising  of  special 
means  for  the  rapid  and  economical  production  of  special  work 
that  his  ingenuity  is  utilized.  The  ability  to  devise  special  tools 
for  special  work  is  one  to  be  prized,  and  should  always  be  en- 
couraged and  developed.  In  this  chapter  are  illustrations  and 
descriptions  of  a  large  variety  of  special  tools,  fixtures,  devices, 
arrangements,  and  novel  methods  for  metal-working ;  by  making 
himself  familiar  with  them  the  mechanic  will  find  no  difficulty  in 
devising  means  for  the  rapid  production  of  any  special  part; 
while  the  descriptions  of  the  proper  ways  to  make  them  will 
show  how  to  avoid  all  unnecessary  expense  and  labor. 

A   SET   OF   TOOLS   FOE  MACHINING   A   CAM. 

The  illustrations  show  a  set  of  tools  for  machining  a  repeti- 
tion casting  of  unusual  shape,  which  was  used  as  a  cam  on  an 
automatic  machine  for  making  fruit-baskets,  and,  as  some  of  the 
tools  are  of  a  novel  and  improved  design,  a  slight  description  of 
them  will  suggest  their  use  for  other  work. 

The  casting  machined  is  shown  in  Fig.  315.  It  is,  to  say  the 
least,  a  rather  difficult  piece  to  machine,  because  of  the  irregular 
cam  surface.  This  cam  surface  was  required  to  be  finished  very 
accurately  and  so  that  the  castings,  when  finished,  would  inter- 
change perfectly.  The  other  portions  of  the  casting  to  be  ma- 
chined so  as  to  interchange  were  the  boring  and  reaming  of  the 

300 


INTERCHANGEABLE  MANTJFA  CTUEING. 


301 


hole  A,  the  facing  of  the  hub  at  G,  of  the  sides  C,  and  the  finish- 
ing of  the  conical  surface  at  B.     The  hub  B  was  left  rough. 

The  number  of  operations  required  to  finish  the  casting  was 
three — the  first  being  done  in  the  turret-lathe  and  the  other  two 


Fig.  315. 


in  the  engine-lathe.  The  first  operation  consisted  of  boring  the 
hole  A  and  reaming  it,  facing  the  hub  G,  and  machining  and  fin- 
ishing the  conical  surface  B.     The  tools  used  in  this  operation 


Fig.  346. 


are  shown  in  Figs.  346  to  350.  Fig.  346  is  a  combination  boring 
and  hub-facing  tool  used  to  bore  the  hole  A  and  face  the  hub  G 
at  the  same  time.     It  consists  of  a  long  stem  H,  with  the  cutter 


Fig.  347. 


Jin  a  slot  in  the  end  held  by  the  taper-pin  J,  and  the  hub-facing 
tool-holder  K,  which  is  located  on  the  bar  by  the  set-screw  L, 
the  point  of  which  screws  into  a  milled  channel  in  the  cutter- 
bar,  as  shown  at  Q.     The  hub-facing  cutter  iVis  held  in  position 


302 


TOOL-MAKING   AND 


by  the  two  set-screws  -ZV  N.  P  is  the  usual  split  bushing  as  used 
in  the  turret-lathe. 

For  reaming  the  hole  A  the  reamer  Fig.  357  is  used.  This 
reamer  consists  of  the  body  Q,  of  tool  steel,  and  six  cutters  or 
blades  T.  These  blades  are  let  into  inclined  channels,  as  shown 
by  the  dotted  lines  at  U  U,  to  allow  the  readjustment  after  being 
worn,  or  after  grinding.  The  blades  are  held  by  taper-headed 
screws  W  which  are  let  into  the  centres  of  the  narrow-sawed  slots 
V.  By  tightening  these  screws  the  metal  is  forced  tightly  against 
the  blades,  thus  holding  them  securely. 

Fig.  348  shows  the  tool  used  for  roughing  off  the  conical  sur- 
face S.     The  tool  has  three  cutting -points  K  and  is  gradually 


Fig.  348. 


slid  along  under  the  surface  by  the  hand-lever,  the  shank  of  the 
tool  being  held  in  the  tool-post.  This  surface  was  finished  by  a 
flat-bladed  tool  of  sufficient  width  to  take  the  entire  line  at  once. 
The  second  operation,  facing  the  two  sides  C  C,  thus  sizing 
the  width  of  the  cam  face,  is  done  in  the  lathe  by  the  special 
double-facing  tool,  Fig.  349.     Three  castings  are  located  on  an 


INTERCHANGEABLE  MANUFACTURING.         303 

arbor  at  once  and  fastened  by  a  nut.     The  tool  is  held  in  the 
tool-post  in  the  usual  way. 

The  last  operation,  machining  the  cam  surface,  was  the  most 
difficult.  It  also  was  done  in  the  lathe  with  four  special  fixtures. 
These  were:  A  special  slide-rest  for  the  cutting-tool,  a  special 


Fig.  349. 


cross-slide  for  the  lathe,  a  combined  master-cam  and  chuck,  and 
a  locating-  and  supporting-stud  for  the  work.  These  fixtures,  in 
position  on  the  lathe  with  the  work,  are  shown  in  Figs.  350  and 


Fig.  350. 

351.  The  master-cam  and  chuck  was  a  forging,  which  was  first 
fitted  to  the  spindle  of  the  lathe,  after  which  the  chuck  portion 
was  finished  with  an  internal  conical  surface  at  1 1  as  a  locating- 
point  for  the  conical  surface  D  D  of  the  work.  The  cam  portion 
was  then  laid  out  and  finished  on  the  universal  milling-machine. 


304 


TOOL-MAKING  AND 


The  stud  or  arbor  for  the  work  was  of  tool  steel  finished  as 
shown,  hardened  and  screwed  tightly  into  the  chuck  portion  of 
the  master-cam,  shouldering  on  it  at  II H  as  shown ;  the  surface 
M  was  then  ground  to  fit  the  work. 

The  special  cross-slide  for  the  lathe  is  in  reality  a  compound 
rest,  the  only  difference  being  that  the  smaller  rest  does  not  swivel. 
The  cam-roller  was  of  tool  steel  and  was  hardened  and  ground 
to  a  smooth  finish  and  located  on  a  hardened  and  ground  jfin  G 


Pig.  351. 

within  the  bracket  K.  A  chain  It  is  attached  to  the  hook  at  the 
back  of  the  slide  and  is  supported  by  a  roller  at  the  back  of  the 
lathe,  with  a  heavy  weight  fastened  to  the  hanging  end  of  it. 
Thus  the  movement  of  the  cross-slide  is  derived  from  the  master- 
cam  S  S  working  against  the  cam-roller.  As  can  be  seen,  the 
construction  of  the  cross-slide  is  strong  and  the  rigidity  of  the 
cutting-tool  is  insured.  The  cam  surface  was  first  turned  to 
within  a  few  thousandths  of  an  inch  of  the  finish  size  and  then 
finished  to  gauge  by  grinding — this  being  easily  accomplished  by 
the  use  of  a  small  tool -post  grinder  driven  by  a  round  belt  from 
a  drum  overhead. 

CUTTING  A   COARSE-PITCH   SCREW. 

Fig.  352  is  a  sketch  of  a  coarse-pitch  screw  which,  because  of 
the  unusual  pitch,  was  cut  and  finished  under  difficulties.  The 
screw  was  30  inches  long,  2  inches  in  diameter,  with  one  thread 
to  3  inches.  After  rigging  up  the  gears  on  the  strongest  lathe  in 
the  place  it  was  fouud  that  the  slowest  speed  we  could  get  was 
too  fast,  and  after  breaking  all  the  teeth  a  new  pair  of  gears  was 


INTERCHANGEABLE  MANUFACTURING.  305 

got  out  to  replace  the  broken  ones.  A  piece  of  machine  steel 
was  turned  up  and  reduced  at  one  end  to  screw  into  the  tapped 
hole  for  the  gear-screw  iu  the  end  of  the  lead-screw  of  the  lathe, 
and  an  8-inch  pulley  keyed  on  this  extension  piece.  A  spare 
countershaft  was  now  located  and  fastened  to  the  floor.  The 
driving-belt  was  removed  from  the  lathe  and  we  then  belted 


Fig.  352. 

from  the  main  shaft  to  the  countershaft  on  the  floor  and  from 
the  couutershaft  to  the  pulley  of  the  lead-screw.  We  thus  re- 
versed matters,  and  instead  of  the  lathe-spindle  driving  the  lead- 
screw,  we  had  the  lead-screw  drive  the  spindle.  Thus  while  the 
lead-screw  fed  the  thread-tool  at  the  proper  speed  the  work 
turned  very  slowly  and  the  screw  shown  and  several  others,  as 
well,  were  finished  without  any  further  trouble. 

MAKING    THIN  THREADED   BRASS   EINGS. 

In  Figs.  353  and  354  respectively  are  shown  the  means  used 
for  accomplishing  a  nasty  little  job  in  a  very  simple  manner. 
We  were  making  a  lot  of  thirty -two  acetylene-gas  lamps,  and 
during  the  process  of  manufacture  it  was  necessary  to  make  and 
sweat  a  threaded  brass  ring  into  one  of  the  shells.  These  brass 
rings  were  made  from  2-inch  brass  tubing  and  were  required  to 
be  finished  to  ^-inch  wide  and  threaded  22 -pitch.  The  tubing 
had  a  wall  of  only  Jg-inch,  and  as  it  was  impossible  to  cut  off 
and  thread  the  rings  in  the  usual  manner  in  the  lathe,  the  fol- 
lowing simple  means  were  used:  A  piece  of  soft  wood  was 
turned  up  on  centres  to  fit  a  length  of  tubing,  as  shown  in  Fig. 
353 — finishing  one  end  somewhat  smaller  than  the  other,  so  that 
the  tubing  could  be  forced  on.  Then  by  driving  this  wooden 
arbor  between  the  centres,  the  rings  were  cut  off  with  ease,  as 
shown,  without  in  the  least  affecting  their  trueness.  After  being 
cut  apart  the  rings  would  come  off  the  arbor  easily.  The  burrs 
were  then  removed  with  a  hand-tool,  and  the  rings  were  threaded 

by  holding  and  locating  them  in  a  wood -chuck  of  the  shape 
20 


306 


TOOL-MAKING  AND 


shown  in  Fig.   354.      This  chuck  was  of  soft    wood  and  was 
turned  at  G  so  as  to  allow  of  its  being  held  in  the  regular  lathe- 


7yr—  t— ,- 


FIG.  353. 

chuck ;  then  bored  ont  on  the  face,  so  that  a  brass  ring  would  fit 
tightly  within  it  and  true  itself  against  the  shoulder  at  H  H. 

Four  round-head  screws  at  J  J  J, 
when  tightened  down  against  the 
edge  of  the  ring,  also  helped  to  hold 
it.  The  rings  were  threaded  in 
this  manner  by  the  usual  threading  - 
tool  and  fitted  to  a  plug,  and  were 
removed  from  the  chuck  by  screw- 
ing the  plug  in  for  a  few  threads 
and  pulliug  the  ring  out.  Some  of 
the  rings  would  not  fit  the  chuck 
tightly,  but  by  taking  a  piece  of 
wet  waste  and  wetting  the  locating 
portion  of  the  chuck,  it  would 
shrink  sufficiently  to  hold.  Any 
one  who  has  ever  tried  work  of 
this  kind  with  the  usual  means  at  hand  in  the  lathe,  will  appre- 
ciate this  simple  and  effective  method. 


FIG.  354. 


A  DEILL-PEESS   JOB. 

The  sketch,  Fig.  355,  shows  how  an  unusual  job  was  accom- 
plished in  a  simple  manner  with  the  best  means  available,  which 
were— to  say  the  least — not  meant  for  the  job.  The  work  was  a 
base  casting  of  a  two-cylinder  pump  model,  and  it  was  necessary 
to  bore  two  lf-inch  holes  in  it  in  the  position  shown.  The  lathe 
we  had  was  too  small  to  allow  of  swinging  it  on  the  face-plate, 
and  the  only  drill-press  in  the  shop  (which  was  a  private  experi- 
mental shop)  was  an  8 -inch  sensitive  drill.     So  by  means  of  the 


INTERCHANGEABLE  MANUFACTURING.         307 

adjustable  cutting-tool  shown  we  did  the  job  on  the  small  drill. 
First  we  drilled  and  reamed  two  small  holes  the  required  distance 
apart  for  the  centres,  as  shown  at  K,  as  locating-  and  truing-points 
for  the  tit  M  of  the  tool  R  as  shown.     The  tool  was  fastened  in 


Fig.  355. 


the  chuck  and  the  work  located  and  clamped  to  the  table  and 
the  holes  finished  as  shown  in  the  sketch.  The  tool  used  for 
this  job  can  be  used  for  a  variety  of  others  as  well. 


A  "STEP- JIG." 

The  sketch,  Fig.  356,  is  meant  to  show  one  end  of  a  hard  rub- 
ber plate  which  was  accurately  finished  on  the  side  to  7|  inches 
wide,  5^  feet  long  and  to  f -inch  thick.     In  this  rubber  plate  there 


Fig.  356. 


were  to  be  drilled  fifty-two  rows  of  holes,  ^-inch  apart  and  625 
holes  in  each  row,  the  size  of  a  No.  60  drill.  The  number  of 
holes  in  all  was  32, 500,  and  each  and  every  one  of  these  holes 


308 


TOOL-MAKING  AND 


description  is  required. 


Qc 


*eQ 


i°  °j 


were  required  to  be  accurately  spaced,  as  the  rubber  plate  was 
to  be  used  as  a  part  of  the  mechauism  of  a  music-box,  a  steel  pin 
being  afterward  inserted  into  each  hole.  There  was  to  be  a 
^-inch  margin  on  all  four  sides  of  the  plate. 

The  jig  used  for  drilling  and  spacing  the  holes  is  shown  in 
two  views  in  Fig.  357.     As  the  sketch  explains  itself,  very  little 

As  shown,  there  is  one  row  of  fifty -two 
holes  running  in  a  straight  line 
from  J  to  J,  and  ^-inch  from  the 
holes  at  the  extreme  ends  of  this 
line  other  holes  as  shown  at  1  1. 
These  two  holes  are  for  spacing  the 
rows  of  holes  in  the  plate  when 
drilling,  by  drilling  the  first  hole 
^-inch  from  the  end  of  the  plate 
and  then  locating  the  jig  for  the 
next  row  by  inserting  the  two  locat- 
ing-pins  K  K  into  and  through  the 
holes  1 1  and  into  those  coinciding 
in  the  plate.  The  holes  in  the  jig 
were  spaced  and  located  in  the 
universal  milling-machine  by  using 
a  small  stiff  centre -drill  for  cen- 
tring all  holes,  and  afterward  drill- 
ing and  reaming  them  on  the  sensi- 
tive drill.  The  manner  in  which  the  jig  is  used  and  the  work 
drilled  can  be  understood  from  the  sketches.  The  drilling  of 
these  32,500  holes  took  some  time,  and  after  each  day's  work 
on  them  it  was  necessary  to  lay  the  rubber  plate  on  the  planer- 
bed  and  put  heavy  weights  on  it  so  as  to  prevent  it  from  warping 
during  the  night. 


io  pj 


Fig.  357. 


A   DEILLHSTG  JOB  IN  THE   PLAKEK. 

I  saw  the  following  combination  used  to  advantage  one  day 
while  looking  through  a  small  country  jobbing-shop.  It  consisted 
of  a  1-inch  drill,  a  lathe-centre,  a  dog,  and  a  stick  of  wood  about 
three  feet  long.  They  were  used  for  drilling  three  1-inch  holes 
in  the  bed  of  an  old  planer.     The  lathe -centre  was  clamped  in 


INTERCHANGEABLE  MANUFA  CTUR1NG. 


309 


the  tool-post  of  the  planer  and  the  dog  fastened  to  the  shank  of 
the  1-inch  drill.  The  point  of  the  drill  was  entered  into  a  cen- 
tre-punch mark  in  the  planer-bed,  and  the  point  of  the  centre  en- 


FiG.  358. 

tered  into  the  shank  end  of  the  drill.  With 
one  hand  the  drill  was  turned  by  using  the 
stick  of  wood  as  a  lever,  and  with  the 
other  the  tool-head  was  fed  down.  In  this 
manner  the  holes  were  drilled.  While  the  use  of  the  lathe-centre 
and  the  cross-head  as  an  ''old  man"  was  all  right,  I  thought 
that  the  dog  and  stick  method  was  rather  obsolete,  until  the 
"boss"  of  the  place  told  me  that  they  had  no  ratchet. 


A   SPRING- WINDING  FIXTURE. 

Fig  358  shows  two  views  of  a  simple  and  handy  little  spring- 
winding  fixture  which,  as  the  sketches  show  its  construction 
clearly,  requires  little  description.  The  body  T  is  a  piece  of 
finished  ^--inch  square  mild  steel,  and  one  end  is  constructed  and 
fitted  for  winding  gauged  springs,  while  the  other  end  is  for 
closed  springs.  The  end  for  the  gauged  springs  has  a  hole 
through  it  at  Z  for  the  rod  L  on  which  the  spring  M  is  wound. 
For  a  gauge  for  winding  the  springs,  the  spring  U  is  used,  it 
being  located  and  fastened  to  the  sides  of  T  by  the  small  clamp 
Y.  V  is  a  small  plate  fastened  to  the  body  at  X,  with  a  guide- 
way  at  W  for  the  wire.  When  in  use  the  rod  L  on  which  the 
spring  is  to  be  wound  and  the  end  of  wire  are  fastened  in  the 
lathe-chuck,  the  projecting  end  of  the  rod  entering  the  hole  Z  in 
the  winder.  Then  the  winder  is  given  a  couple  of  turns  around 
the  rod,  so  that  the  gauger  U  will  have  twisted  around  the  wire. 


310  TOOL-MAKING  AND 

The  fixture  is  then  fastened  in  the  lathe  tool-post  and  the  lathe 
started,  holding  the  wire  tight  by  the  hand  and  letting  it  run 
down  the  guideway  as  shown. 

The  other  end  of  the  winder  is  used  as  shown.  The  screws 
P  P  and  0  0  are  for  adjusting  a  guideway  for  the  wire  which 
passes  under  the  roller  Q  and  is  wound  around  the  rod  S,  as 
shown  at  R. 

A  SOLDEEING  FACE-PLATE. 

One  of  the  handiest  things  around  the  jobbing-shop  is  a  solder- 
ing face-plate.  The  number  of  small,  odd,  and  intricate  little 
jobs  which  can  be  accomplished  with  ease  by  its  use  is  surpris- 
ing. The  one  we  had  was  fitted  up  to  locate  and  fasten  on  the 
face-plate  of  the  Hendey-Norton  lathe.  It  consisted  of  a  disk 
of  cast  composition  about  one  inch  thick  and  slightly  under  the 
diameter  of  the  face-plate.  After  being  faced  on  one  side  it 
was  located  and  fastened  to  the  face-plate  by  means  of  four 
countersunk  head-screws  which  were  let  in  from  the  back,  thus 
allowing  of  its  easy  removal  when  through  with  it.  One  of  these 
plates  should  be  kept  in  every  tool-room,  and  one,  1  inch  thick, 
will  last  a  long  time  and  pay  for  itself  over  and  over  again  be- 
fore being  worn  out. 

MAKING   COLLET   SPKUSTG   CHUCKS. 

The  following  kink  I  found  very  handy  when  making  collet 
spring  chucks  of  the  shape  shown  in  Fig.  359.  After  finishing 
them  in  the  lathe,  leaving,  of  course,  enough  stock  to  lap  and 
grind  to  a  finish,  face  them  on  an  arbor  and  saw  the  spring  slots 

as  shown — that  is,  at  the  end  of  each 
slot,  as  shown  at  T  and  V,  instead 
of  cutting  completely  through  at  this 
point,  leave  a  very  thin  wall  of  about 
^-inch  long  at  the  end  of  all  the  cuts. 
Then  harden  and  temper  the  chuck 

FIG.  359. 

as  desired,  and  after  lapping  the  in- 
side to  size,  place  on  another  arbor  and  grind  the  tapers  as  re- 
quired. Then  take  a  small,  narrow  broach  and  by  entering  it 
into  the  slots  and  hitting  it  a  sharp  blow  with  a  hammer  the  thin 


INTERCHANGEABLE  MANUFACTURING.         311 

wall  will  break  through.  This  kink  I  have  used  to  the  best  ad- 
vantage iu  shops  which  had  no  grinding  facilities.  When  pro- 
ceeding as  aforesaid,  it  was  possible  to  finish  the  outside  and 
tapers  to  size  before  hardening  without  the  possibility  of  the 
chucks  running  out  to  a  noticeable  extent.  Of  course  in  work 
of  the  utmost  accuracy  this  method  would  not  do.  But  then 
again,  work  of  the  utmost  accuracy  is  not  accomplished  in  shops 
where  the  tool  facilities  are  not  up  to  date. 

A  FLAKING-STICK. 

In  Fig.  360  is  shown  a  sketch  of  a  little  kink  which,  while  no 
doubt  old  to  many,  may  be  new  to  some.  It  is  a  flaking-stick, 
and  may  be  used  to  produce  that  circular  flaking  often  seen  on 
the  inside  of  watch-cases  and  often  desired  for  a  finish  on  differ - 


-Lead  pencil 


Emery  doth 
Fig.  360. 

ent  polished  small  parts.  It  consists  of  a  stump  of  a  lead-pencil 
and  a  piece  of  emery-cloth,  as  shown,  fastening  both  in  the  chuck 
of  the  small  drill -press,  then  running  it  fast  and  coming  down 
on  the  work  for  a  second  and  then  shifting  it  and  coming  down 
again.  The  finished  effect  is  fine  when  a  little  care  is  taken  to 
move  the  work  evenly. 

DRILLING   HOLES   IN   A  HELICAL  SURFACE. 

Fig.  361  shows  a  drilling  fixture,  with  the  work  in  position, 
for  drilling  a  500  lot  of  malleable  iron  castings  of  the  shape 
shown.  In  these  castings  it  was  necessary  to  drill  twelve 
equally  spaced  holes  c  c  c  around  the  helical  portion.  The  de- 
sign of  the  fixture  and  the  manner  in  which  it  was  used  are 
shown  clearly  and  can  be  understood  without  description. 

MILLING  IN   THE  DRILL-PRESS. 

Fig.  362  shows  the  use  of  a  small  fixture'  for  milling  in  the 
drill-press,  a  portion  J  out  of  a  small  eccentric  cam-shaft  P. 


312 


TOOL-MAKING   AND 


F  is  the  fixture  in  which  the  work  is  located  in  the  hole  G.    The 
work  is  located  and  prevented  from  turning  while  being  ma- 


^^ 


f~ ~J 


Nut  tor  Supporting 
Work 

I 


-Locating  Pia 


Collar  wilh  Hardened 
Bushlugs 


FIG.  361. 


chined  by  a  portion  of  P  resting  in  a  turned  depression  in  the 
top  of  the  fixture  at  H.  A  hardened  taper-pin  R,  with  a  flat 
face  to  bear  against  the  work,  secures  it,  as  shown.  L  is  the 
shank  of  the  cutter-holder  which  is  fitted  to  the  drill-press  spin- 


■Wf^ 


Fig.  363. 


die.  The  cutter  K  is  keyed  on  and  further  secured  by  the  nut 
and  washer.  The  stem  M  of  the  cutter-holder  runs  in  the  hard- 
ened bushing  N  while  the  work  is  being  machined. 

A  SIMPLE   LATHE-CHUCK. 

In  Fig.  363  are  two  views  of  a  simple  chuck  used  for  locating 
and  holding  a  cast-brass  ring,  while  the  inside  at  D  D  was  being 


INTERCHANGEABLE  MANUFACTURING. 


313 


bored  and  the  edge  E  E  rounded  by  the  tool  at  the  right. 
There  were  a  hundred  of  these  rings  to  be  done  and  the  portions 
designated  were  the  ouly  points  finished.  The  chuck  proper 
was  of  cast-iron  fitted  at  A  to  the  lathe-spindle,  and  the  face  bored 
out  for  the  work,  as  shown.  The  three  set-screws  B  at  the  back 
were  for  locating  the  work  true  sidewise,  while  the  three  around 
the  outside  at  Cwere  for  centre -truing  and  holding  it.  To  fasten 
or  release  the  work  it  was  only  necessary  to  tighten  or  loosen  one 
of  the  screws  C. 


TEIMMING   SHEET-BBASS   BLANKS. 

The  arrangement  shown  in  Fig.  364  was  used  for  rounding 
the  edges  of  sheet-brass  blanks  y^-inch  thick  and  If  inches  in 
diameter.  There  were  2,000  of  these  blanks  and  they  were 
punched  in  a  plain  blanking-die.  Finishing  the  blanks  by  the 
means  available  in  a  jobbing-shop  was  impossible,  and  for  a 


Truing  BtrfEe: 


Sc^ 


1      2M) 

a 


Fig.  364. 

while  we  thought  that  we  were  "up  against  it";  but  one  of  the 
men.  who  had  done  considerable  mould  making  in  his  time,  told  of 
a  method  which  he  had  seen  used  with  great  success  for  finishing 
the  edges  of  "poker-chips."  This  method  was  adopted,  with  the 
result  that  the  job  was  accomplished  with  ease  and  at  a  very  low 
cost.  The  piece  A  is  fitted  to  a  hole  in  turret  of  a  small  screw- 
machine,  with  a  piece  of  hard  spring  rubber  B  attached  to  the 
projecting  end  of  the  press  R.  A  duplicate  of  this  piece  R  is 
held  in  the  chuck  on  the  spindle  of  the  screw-machine.  The 
rounding-tool  is  fastened  in  the  front  tool-post,  while  the  turn- 
ing-buffer is  located  in  the  back  one.  To  machine  a  blank  it  is 
held  by  the  fingers  against  C,  while  the  piece  R  with  the  rubber 


314 


TOOL-MAKING  AND 


front  B  is  brought  against  it  by  moving  the  turret  up  and  forc- 
ing the  rubber  against  the  blank,  which  is  trued  and  sufficient 
pressure  applied  to  hold  it.  The  rounding  off  is  then  accom- 
plished by  the  tool,  and  the  blank,  is  released.  The  blanks  were 
all  finished  to  size  in  this  manner  without  any  trouble. 

A  DIE-MAKING  KINK. 

Fig.  365  shows  a  little  kink  which  to  the  best  of  my  knowl- 
edge is  original.  It  consists  of  simply  taking  the  upper  half  of 
a  brass  door-key  and  soldering  it  to  the  centre  of  a  templet  for  a 
handle.     When  the  templet  is  large,  as  is  the  one  shown,  the  sol- 


FiG.  365. 


FIG.  366. 


dering  of  the  key  to  it  iustead  of  a  piece  of  wire  is  a  great  con- 
venience. When  the  die  is  finished  the  key  can  be  removed  and 
laid  away  in  one's  drawer  until  required  again. 


A   SIMPLE  SLOTTING  FIXTUEE. 

Fig.  366  shows  three  views  of  a  simple  slotting  fixture  which 
was  used  to  advantage  for  milling  the  slots  T  T  in  the  cast- 
ing shown.  There  were  about  200  of  these  castings,  and  they 
were  required  to  interchange.  Before  slotting  they  were  bored 
and  reamed  at  X  X  and  the  hubs  were  faced.  The  slotting 
fixture  consists  of  a  machine-steel  plate  into  which  the  cen- 
tral locating-stud  is  riveted ;  and  two  dowel-pins  are  let  into  the 
back,  as  shown.  These  pins  coincide  with  two  holes  drilled  in 
the  stationary  jaw  of  the  miller-vise.  A  gauge-pin  in  the 
front  of  the  plate,  at  the  right,  serves  to  locate  the  work  as 
required. 


INTERCHANGEABLE  MANUFACTURING. 


315 


KEY-SEATING   IN  THE   POWER- PRESS. 

Fig.  367  shows  the  method  used  for  cutting  a  keyway  in  the 
small  cast-iron  collar  at  D.  These  collars  were  used  in  a  large 
number ;  for  that  reason  the  means  shown 
were  adopted  for  cutting  the  keyway. 
The  broach  is  fastened  in  a  holder,  while 
the  collar  A  is  located  beneath  the  stripper 
of  the  die-bolster.  The  stripper  and  lo- 
cating depression  are  cut  away  at  the 
front  for  facing  and  moving  the  work. 
The  guide  is  of  tool  steel,  hardened,  and 
fits  the  circular  portion  of  the  broach 
snugly.  The  finishing  of  the  keyways 
in  the  power-press  by  the  means  shown 
fig.  367.  proved    very    satisfactory,    far   more   so 

than  by  the  old  way  of  forcing  the  broach  through  under  the 
arbor-press. 


HAND   CUT-OFF   AND   FORMING-TOOL. 

The  tool  here  shown  in  Fig.  368  was  used  for  the  rapid  pro- 
duction of  small  work  as  sketched  in  W,  Fig.  271,  forming  and 
cutting  off  at  the  same  time.  As  a  rule,  all  work  of  this  kind 
is  done  in  a  turret-lathe  or  screw-machine.  Pieces  of  the  first 
shape  shown  in  Fig.  373  were  produced  by  the  present  simple  de- 
vice at  the  rate  of  8, 000  a  day. 

The  tool  was  composed  of  two  main  parts,  A  the  body,  Fig. 
269,  and  B  the  slide  or  tool-holder,  Fig.  270.  Having  been  planed 
on  the  various  sides  it  was  set  up  and  dovetailed  for  B  to  an  an- 
gle of  eight  degrees  with  the  bottom.  A  hole  was  then  bored  and 
reamed  at  E  for  the  bushing,  and  hole  D  tapped  for  the  set-screw. 
A  rib  was  cast  up  from  the  base  and  a  hole  drilled  and  tapped 
through  its  entire  length  at  C  for  the  adjustable  stop  -  screw  H. 
A  hole  was  also  cut  through  the  bottom  at  P  as  clearance  for  the 
lower  handle  T.  The  slide  or  tool-holder  B  of  cast-iron  was  then 
machined  and  fitted  to  the  dovetail  in  A  so  as  to  run  freely ;  a 
recess  was  also  let  in  at  J  for  locatiug  the  tool  or  cutter.     A  flat 


316 


TOOL-MAKING  AND 


piece  of  machine  steel,  D,  fastened  by  the  two  screws  as  shown, 
served  as  strap  for  holding  the  tool.  A  bushing  of  tool  steel  E 
was  then  finished  to  the  size  of  the  stock  to  be  used  and  fitted 
tightly  within  A.  This  was  cut  away  in  front  for  clearance  for 
the  tool  and  left  full  in  the  back  to  steady  the  side.  This  was 
then  hardened  and  slightly  drawn.  A  stop -screw -ST  was  then 
made  which  consisted  of  a  long  threaded  stem  to  fit  the  hole ;  the 
head  was  large  enough  in  diameter  to  serve  as  an  adjustable  stop 
for  regulating  the  length  of  the  work.  The  forming  and  cutting- 
off  tool  C  was  made,  hardened  and  drawn,  and  fitted  and  held  on 
B  as  shown ;  its  cutting-face,  when  the  side  was  advanced,  coin- 
ciding with  the  centre  of  the  hole  in  the  bushing  E.     The  oper- 


A  -4M 

1-iQl- 

/■:' 

^Sss^^ 

Fig.  368. 


ating  lever  T  was  then  made,  the  lug  J  fitting  within  the  hole  in 
the  slide  B,  the  fulcrum  of  the  lever  being  held  between  the  two 
lugs  projecting  down  from  the  bottom  of  A.  A  hole  was  then 
drilled  in  it  for  the  adjusting-screw  or  stop  A  to  prevent  the  tool 
from  going  too  far.  Two  stiff  pull-springs  A  A  were  fastened 
by  pins  in  A  and  B  respectively,  with  sufficient  tension  to  bring 
the  slide  back  when  the  pressure  on  the  lever  was  released.     The 


INTERCHANGEABLE  MANUFACTURING. 


317 


parts  were  then  assembled  in  the  way  shown.  The  rod  used 
came  in  20-foot  lengths,  one  end  of  which  entered  the  hollow 
spindle  of  the  speed -lathe  and  was  allowed  to  project  from  the 


jL 


v^ 


o 

Wttftt 

p 

o 

Fig.  369. 

chuck  almost  four  feet.  This  end  was  entered  within  the  bush- 
ing E ;  the  lathe  was  run  at  its  highest  speed  and  the  tool  held 
in  both  hands.  Pressing  on  the  handle,  the  slide  B  moved  far 
enough  to  enable  the  tool  C  to  form  and  finish  the  first  end.     The 


~  i!   "i~ 

Side  of  Slider  B 

K 

"XT 

j 

m  b 

JDji 

Plan  of  B 

Fig.  370. 

Q  1 

l 

A 

5 

? 

<J  <■* 

= 

«<i 

3 

Fig.  371. 


stop  ITvas  then  set  and  the  tool  moved  along  until  the  finished 
end  rested  against  it,  when  the  other  end  was  finished  and  cut 
off  and  also  the  end  of  the  next  piece  formed,  and  so  on.     We 


31S 


TOOL-MAKING   AND 


cut  rods  from  smallest  sizes  up  to  J-mch  iu  diameter  iu  this  way 
aud  beat  the  other  ways  by  a  large  margin,  the  only  changes  nec- 
essary being  to  replace  bushing  E  and  the  cutting-tool  C  with  the 
others. 


FILLING-JIG   FOR  THE   SPEED-LATHE. 

The  jig  here  shown  in  Fig.  372  was  used  for  milling  the  side 
at  Tof  the  piece  shown  in  Fig.  373,  which  was  made  in  the  screw- 
machine.     After  the  casting  A  for  the  base  was  planed  on  both 


Fig.  372. 


Fig.  373. 


sides,  the  two  holes  Q  Q  were  drilled  for  fastening  it  to  the  lathe. 
The  swivel  stud  C  of  machine  steel  was  then  made ;  the  case  B, 
of  cast-iron,  was  turned  and  bored  to  allow  C  to  move  freely 
within  it.  A  ^-inch  slot  f  -inch  deep  was  milled  through  the 
centre  of  the  top  of  C  and  then  fastened  to  the  base  B  by  four 
screws.  A  casting  E  was  planed  and  the  vertical  slot  for  the 
lever  F  to  move  in  was  worked  out  to  fit  the  lever  nicely  side- 
wise.  An  opening  was  cut  away  at  the  farther  side,  as  indicated 
by  dotted  lines  at  H,  for  an  outlet  sidewise  for  the  lever.  The 
hole  for  the  adjusting-screw  J"  was  then  drilled  and  tapped  in 
the  top  and  the  casting  fastened  to  the  front  of  A  by  screws, 


INTERCHANGEABLE  MANUFACTURING  319 

leaving  the  slot  for  the  lever  in  line  with  the  centre  of  the  stud 
C.  The  lever  F  was  then  placed  in  the  slot  in  C,  and  a  hole  was 
drilled  through  them,  both  for  the  pin  G-  which  was  tight  in  C 
and  free  in  F.  The  large  parts  of  the  jig  being  complete,  the 
piece  for  locating  and  holding  the  work  was  made. 

The  work  Fig.  373  was  made  in  the  turret-lathe.  The  groove 
R  around  the  outside  of  the  piece  was  as  near  a  perfect  half- cir- 
cle as  it  was  possible  to  get  it,  and  about  -g^-inch  radius.  At 
first  a  piece  of  machine  steel  was  worked  down  to  the  shape 
shown  by  the  outside  of  K.  This  was  then  fastened  to  the  out- 
side of  the  "lever  Fbj  screws  and  dowel-pins.  A  hole  was  then 
drilled  in  the  centre  of  this  at  M  just  the  size  of  the  work  around 
the  body,  this  hole  cutting  partly  into  F  as  shown,  and  the  shape 
of  the  small  portion  of  the  head  worked  out,  allowing  the  work  to 
rest  nicely  within  it.  The  distance  from  the  centre  of  the  work 
to  the  centre  of  the  groove  R  was  then  found,  and  the  centres 
located  on  the  side  of  the  lever  F  and  two  holes  drilled  through 
the  lever  and  the  piece  K,  cutting  half-way  into  the  hole  M. 
Two  pieces  of  Stub  steel,  NN,  ^-inch  in  diameter  and  the  proper 
length,  rounded  off  at  the  ends,  were  fastened  into  a  flat  steel 
piece  0  so  that  they  would  just  enter  the  two  holes  at  N  N. 
A  round-head  thumb-screw  W  was  let  in  at  P,  enabling  this  piece 
to  be  inserted  and  withdrawn  readily. 

The  jig  being  complete,  it  was  fastened  to  the  lathe  crosswise 
and  a  cutter  placed  on  a  mandrel  between  the  centres.  The  jig 
was  then  placed  so  that  the  work  would  come  central  one  way, 
and  off  to  the  side  the  proper  distance  the  other  way.  The  lever 
F  was  dropped  down  and  moved  sidewise  out  through  the  open- 
ing H.  This  left  the  part  for  the  work  to  go  in  clear  of  the  cut- 
ter. The  work  was  then  inserted  and  the  lock-pins  N  N  were 
thrust  in,  thereby  binding  the  work  securely.  The  lever  was 
then  re-entered  into  the  slot  H  and  raised  to  a  height  sufficient 
to  mill  the  work  to  the  proper  depth,  when  the  top  of  the  lever 
encountered  the  top  screw  J.  We  did  quite  a  variety  of  different 
milling  and  cutting  of  this  kind  with  this  jig. 


320 


TOOL-MAKING   AND 


JIGS   AND   FIXTUBES   FOR  ADJUSTABLE   STOBS  AND 
SBINDLE-BACKS. 

Figs.  374  and  375  show  in  two  views  an  adjustable  stop  com- 
plete, as  used  on  drill-press  spindles.  As  shown,  it  consists  of  a 
casting  with  the  centre  hole  A  bored  and  reamed  to  fit  the  spin- 


FIG.  374. 


Fig.  375. 


die  of  the  press  at  the  upper  end.  It  is  also  drilled  at  each  end 
for  a  screw  and  slotted  at  D.  The  screw  C  is  for  tightening 
it  on  the  spindle.  The  adjustable  stop-screw  F  consists  of  a 
knurled  screw  i^and  a  jam-nut,  as  shown.  For  the  machining 
and  finishing  of  the  casting  three  operations  were  necessary. 

For  the  first,  that  of  boring  the  centre  hole  A  and  facing  one 
side  at  B,  the  special  chuck  shown  in  the  two  views  in  Fig.  376 


FIG.  376. 

was  used.  It  consists  of  a  casting  G  of  the  shape  shown,  which 
was  first  chucked  and  a  hole  bored  through  it  at  L.  This  hole 
was  then  enlarged  and  threaded  at  H,  as  shown,  to  fit  the  spindle 
of  the  turret-lathe.  It  was  then  removed  and  the  face  milled 
and  cut  away  as  shown — that  is,  on  the  sides  K  K  and  J — and  a 
straight  cut  to  the  depth  shown  through  the  face  at  1 1  made. 


INTERCHANGEABLE  MANUFACTURING. 


321 


A  hole  was  then  drilled  and  tapped  for  the  clamping-screw  P, 
which  was  reduced  at  one  end  and  fastened  within  the  clamping  - 
jaw  M,  as  shown,  the  plate  0  keeping  it  in  position.  The  chuck 
was  then  screwed  on  to  the  spindle  of  the  turret-lathe,  a  piece  of 
steel  placed  between  the  jaws  M  and  N  at  each  side,  and  the 
screw  P  tightened  so  as  to  clamp  them  securely.  The  two  jaws 
were  then  bored  to  the  diameter  and  depth  shown,  the  radius 
being  the  same  as  that  of  the  largest  circular  diameter  of  the 
casting  Fig.  375,  and  in  depth  so  that  it  would  project  outside 
of  the  chuck  enough  to  allow  of  it  being  faced.  All  this  being- 
done,  the  chuck  was  finished  and  ready  for  work. 

When  using  the  chuck  the  casting  Fig.  375  was  clamped  be- 
tween the  jaws  Maud  N,  and  the  hole  A  was  bored  and  reamed, 
by  means  of  the  turret-tools,  and  faced  by  a  tool  in  the  tool -post 
of  the  slide-rest.  As  will  be  seen,  the  chuck  is  suggestive  for  a 
number  of  different  jobs  on  odd-shaped  castings,  as  it  is  easy  and 
inexpensive  to  construct,  and  also  rapid  in  1  andling  and  produc- 
tion. It  is  a  type  of  chuck  used  quite  extensively  in  the  brass- 
shops,  where  odd-shaped  castings,  for  various  purposes,  such  as 
unions,  etc.,  are  made  in  large  quantities.  When  a  number  of 
different-shaped  pieces — in  number  sufficient  to  allow  of  the  nec- 


n ,     i 


fFTlffllJ 


Si 


H 


j    X      {     T      jOK-T-  - 


"3h 


5   \T^H 


o 


JTZlH 


-r-r 


Fig.  377. 

essary  expense— are  required  to  be  bored  and  reamed  to  a  given 

size,  the  means  shown  are  the  best  for  producing  them.     The 

chuck  shown  can  be  so  constructed,  by  changing  it  to  suit,  as  to 

allow  of  pairs  of  different-shaped  jaws  being  inserted  in  place  of 

the  ones  in  use.     The  way  to  do  this  is  to  finish  the  face  of  the 
21 


322 


TOOL-MAKING  AND 


chuck  with  a  stiff  projection  at  each  side,  and  dovetail  the  jaws 
into  them,  one  of  the  jaws,  of  course,  being  adjustable. 

For  the  next  operation  on  the  casting,  that  of  drilling  the 
holes  at  C  and  irrespectively,  the  drill -jig  shown  in  Fig.  377  is 
used.     It  requires  no  description  to  be  understood. 

For  the  last  operation,  that  of  slotting  the  casting  at  D,  a  sim- 
ple little  fixture  for  use  in  the  milling-machine  is  shown,  and  as 
the  two  views  of  it  with  the  work  in  position,  shown  in  Figs.  378 
and  379,  are  very  clear,  very  little  description  is  necessary.  An 
angular-shaped  casting  A  is  first  planed  and  finished  as  shown, 


fig.  378. 


Fig.  379. 


the  part  B  as  the  base  to  rest  squarely  within  the  milling-ma- 
chine vise.  A  machine-steel  stud  C  is  then  turned  to  fit  the  cen- 
tre hole  A  in  the  casting,  Fig.  375,  and  reduced  at  one  end  so  as 
to  shoulder  against  the  back  of  the  fixture  B,  and  riveted  tightly 
within  it  at  D,  as  shown.  The  pin  is  for  locating  the  casting 
squarely  on  the  fixture.  A  slot  is  cut  through  the  top  in  line 
with  the  centre  of  the  stud  C  and  running  partly  through  it,  as 
shown.  This  in  order  to  get  the  slot  in  the  centre  of  the  cast- 
ing, that  is,  central  with  the  hole  A,  Fig.  375.  In  operation 
the  casting  is  placed  on  the  fixture  as  shown,  and  forced  against 
the  pin  E.  Both  fixture  and  casting  are  then  clamped  in  the 
miller- vise,  and  the  cutter  G  entered  into  the  slot.  When  the 
casting  is  milled,  it  is  removed  and  another  substituted,  and  the 
operation  repeated.  This  little  fixture  is  all  right,  as  it  allows 
of  the  slotting  operation  being  accomplished  uniform  in  all  of  the 
castings,  giving  them  a  neat  and  mechanical  appearance  when 
finished,  and  is  far  superior  to  the  usual  way  of  doing  simple 
jobs  of  the  kind  shown,  namely,  setting  the  casting  central  to  the 
eye,  and  then  going  ahead,  with  the  ultimate  result  that  there 
are  not  two  alike. 


INTERCHANGEABLE  MANUFA  GT  UEING. 


323 


MILLING   SPINDLE-BACKS. 

In  Fig.  380  is  shown,  in  three  views,  a  fixture  which  is  used 
for  milling  drill-press  spindle-racks.  And,  as  it  is  as  practical 
a  device  as  could  be  designed  for  use  in  the  regular  milling- 
machine,  it  is  worthy  of  interest,  handling,  as  it  does,  sixteen  rack 


K  K  K  K 


K  K 


K  K  K  K  K  K 

L— :pi|  H  pal  HHSHSHHHHHFalH  |ca|-L 


SIDE  VIEW 


m^ — ^jffi1 


JT 


END  VIEW 


FIG.  380. 

blanks  at  a  time.  In  design  it  is  both  simple  and  compact  and 
is  so  constructed  that  a  boy  can  operate  it  successfully  while 
running  another  machine ;  as  when  the  cutter  is  set,  the  time  nec- 
essary to  allow  of  the  cutters  running  through  the  entire  sixteen 
blanks  can  be  utilized  in  looking  after  a  different  operation  in 
another  machine. 

In  constructing  the  fixture  a  flat  casting  of  the  shape  shown 
at  H  was  first  secured — in  appearance  resembling  a  die-bolster — 
was  planed  smooth  on  the  top  and  bottom,  and  the  tongue  J 
fitted  to  the  slot  in  the  milling-machine  table.  While  planing 
the  tongue  a  cut  was  taken  off  each  side,  so  as  to  have  them 
square.     The  casting  was  then  transferred  to  the  milling-  machine, 


324  TOOL-MAKING  AND 

when  the  four  rows  of  holes,  sixteen  in  number,  for  the  dowel  - 
and  locating-pins  I  and  J  J  were  drilled.  These  holes  were  for 
locating  the  rack  blanks,  which  had  been  previously  milled  to 
size,  and  the  four  holes  in  each  drilled  in  a  jig  so  that  they  were 
exact  duplicates  of  each  other.  In  drilling  the  holes  in  the  cast- 
ing H  it  was  strapped  on  an  angle-plate,  facing  the  spindle, 
which  was  in  turn  clamped  to  the  extension  plate  on  the  milling- 
machine  table,  taking  care  to  get  the  casting  H  fastened  so  that 
the  tongue  J  was  parallel  with  the  table.  The  first  row  of  holes 
was  then  drilled  by  first  using  a  small  centre-drill  and  spacing 
the  holes  by  means  of  the  dial  on  the  feed-screw  of  the  table,  and 
then  drilling  them  all  in  the  same  manner,  repeating  the  opera- 
tion until  the  four  rows  of  holes  for  dowel-  or  locating-pins  /  / 
and  J  J  were  drilled. 

In  the  spacing  of  the  holes,  so  as  to  get  them  in  the  relation 
to  each  other,  as  shown,  great  care  was  taken  so  as  to  have  them 
coincide  perfectly  with  those  drilled  in  the  racks,  as  these  pins 
locate  the  blanks  square  on  the  fixture  when  in  use.  Sixty -four 
small  pins  were  then  cut  off  to  the  length  shown,  and  rounded  at 
one  end ;  they  were  made  of  Stub  wire  and  driven  tightly  into 
the  holes  drilled  in  the  fixture,  and  an  easy  fit  in  the  holes  of  the 
rack  blanks. 

The  small  clamps  shown  at  K  K,  of  which  there  were  thirty- 
two,  were  then  made  to  the  shape  shown,  by  taking  four  bars, 
long  enough  to  get  eight  out  of  each,  and  milling  them  to  the 
shape  required,  after  which  they  were  cut  into  sections,  which 
were  the  clamps  shown.  The  clamps  were  then  drilled  for  the 
screws  L  as  shown,  and  sixteen  fastened  at  each  side  of  the  fixt- 
ure in  the  jmsition  required,  so  as  to  grip  tightly  the  ends  of  the 
blanks  and  keep  them  flat  and  square  on  the  fixture.  The  heads 
of  all  screws  were  case-hardened. 

The  various  parts  of  the  fixture  were  then  assembled,  and  the 
fixture  complete  strapped  on  the  milling-machine  table  by  means 
of  bolts  through  the  ends  at  1 I,  and  with  the  tongue  S  in  the 
centre  slot.  The  sixteen  rack  blanks  were  then  located  and  fast- 
ened on  the  fixture  by  fixing  them  on  the  pins  1 1  and  J  J  and 
the  clamps  tightened  as  shown  on  the  blanks  M  in  the  plan  view 
of  the  fixture  in  Fig.  380.     This  figure  shows  the  blanks  partly 


INTERCHANGEABLE  MANUFA  CTURING. 


325 


finished,  the  last  one  being  off  to  show  the  pins  for  locating  them. 
Two  cutters  of  the  pitch  required  were  used,  and  the  table  of  the 
miller  raised  so  that  the  full  cut  would  be  taken.  The  feed  was 
then  put  on,  and  the  cut  taken  through  the  entire  sixteen  blanks, 
when  the  table  was  run  back  to  the  starting-point,  moved  over 
the  required  number  of  thousands,  and  the  cut  repeated,  and  so 
on,  until  the  entire  sixteen  blanks  were  finished.  They  were 
then  removed  and  another  lot  located  and  fastened  in  the  same 
manner,  and  the  operation  of  milling  repeated. 

This  fixture  overcomes  the  difficulties  which  are  usually  met 
with  when  milling  one  rack  at  a  time,  by  holding  it  in  the  mill- 
ing-vise. As  when  it  is  done  in  that  manner  it  is  necessary  to 
mill  all  sides  of  the  blank  perfectly  square  with  each  other,  in 
order  to  get  them  to  lay  flat  while  being  cut,  while  by  the  use  of 
this  fixture,  as  shown,  it  is  not  necessary  to  be  so  particular,  as 
the  blanks  are  held  by  means  of  the  clamp  at  either  end,  and 
located  squarely  and  in  line  with  each  other  by  the  pins  shown. 
Another  thing,  the  setting  is  easy  to  accomplish,  as  it  entails  no 
adjustment  of  the  parts. 


JIG   FOR  DRILLING   SMALL  THREAD   DIES. 

Some  years  ago  I  had  a  job  of  making  one  hundred  small 
thread  dies  for  screw-machine  work.     To  have  drilled  them  in 


Fig.  381. 


Fig.  382. 


the  regular  way  would  have  taken  a  great  deal  of  time  and  made 
them  very  expensive,  so  I  made  the  jig  shown  in  Fig.  382  for 
the  purpose. 

First,  I  turned  and  finished  a  bar  of  steel  to  exactly  the  right 
size  for  the  dies  and  then  cut  off  the  blanks,  being  particular  to 


326  TOOL-MAKING. 

get  them  all  the  same  thickness  and  also  to  chamfer  the  corners. 
Fig.  381  shows  the  die  blanks,  which  are  ^-inch  diameter.  Fig. 
382  shows  two  views  of  the  jig,  the  top  and  a  cross  section.  The 
jig  was  made  in  the  shape  of  a  round  box.  B  is  a  piece  of  round 
machine  steel  turned  and  finished  as  shown  with  a  thread  of  10- 
pitch  cut  at  F  which  was  cut  loose  in  order  to  work  the  jig  rap- 
idly. At  the  same  time  the  seat  for  the  blanks  was  turned  out 
at  C  so  that  they  would  just  fit  in  without  play.  A  hole  was 
then  bored  through  at  D  to  give  clearance  when  the  drill  came 
through  and  also  to  let  the  chips  out.  The  jig  proper  A  was  a 
piece  of  round  tool  steel  chucked  and  finished  all  over  in  the  way 
shown.  The  centre  hole  was  drilled  at  the  same  time,  and  a  cir- 
cle was  struck  to  drill  the  other  four  holes  by.  The  outside  was 
heavily  knurled  to  give  the  operator  a  good  grip.  All  holes  were 
reamed  and  slightly  countersunk  to  allow  the  drills  to  enter 
freely,  when  the  work  was  carefully  hardened  and  drawn,  being 
then  ready  for  work.  The  blanks  were  laid  in  at  C,  the  cover  A 
was  screwed  down,  and  the  holes  all  drilled,  and  another  die  in- 
serted, and  so  on  with  them  all.  It  was  surprising  how  quickly 
the  dies  were  made  by  the  use  of  this  jig. 


CHAPTER  XXII. 

Special    Tools,    Fixtures,    Devices,    Arrangements, 

Contrivances,  and  Novel  Methods  for  Metal 

Working. — Continued. 

A  MACHINE  FOE   TWISTING   COEKSCEEWS. 

The  machine  here  shown  was  made  for  twisting  wire  cork- 
screws of  the  type  shown  in  Fig.  383.  The  wire  before  the  twist- 
ing is  shown  below  the  corkscrew.  It  is  "looped"  at  one  end 
and  bent,  while  the  other  end  is  pointed.  The  cutting  off  of  the 
length  of  wire  and  the  pointing  of  one  end  are  accomplished  in 


Fig.  383. 

one  operation  by  means  of  two  simple  tools  in  the  monitor;  the 
tool  used  for  pointing  being  a  "  needle "  box-tool,  and  the  one 
for  cutting  off  a  "chopping-tool."  The  second  operation  on  the 
wire  lengths,  that  of  bending  and  forming  the  "loop,"  is  done 
by  hand,  with  a  simple  bending  fixture  not  of  sufficient  interest 
to  show  here. 

The  drawings,  Figs.  384,  385,  and  386,  of  the  twisting-machine 
show  its  construction  and  little  description  will  be  necessary. 
The  machine  consists  of,  first,  a  body  or  main  casting  on  which 
are  four  standards  for  bearings  for  two  shafts.     The  pulley, 


328 


TOOL-MAKING   AND 


clutch,  and  small  driving-gear  require  no  explanation.  The  wire 
is  clamped  between  two  jaws  H  H,  Fig.  384,  the  upper  one  of 
which  is  raised  or  lowered  by  the  handle  and  two  gears  A  A  turn- 
ing right  and  left  screws.  The  mandrel  or  forming -spindle  X  is 
of  tool  steel  finished  to  fit  easily  within  the  sleeve  K,  which  in 
turn  is  fitted  and  keyed  to  turn  with  the  slide,  back  and  forth 
within  the  main  spindle  V  by  a  key  at  D.  A  handle  at  Z  fast- 
ened to  the  forming -mandrel  by  the  set-screw  W  keeps  the  man- 
drel stationary,  by  a  round-headed  pin  entering  the  back  at  Y, 
while  the  sleeve  with  the  main  spindle  rotates  and  twists  the 


Spindle  Gear 


M  /Driving  Spindle Vt-        ,  ^ 


Fig.  384. 

wire.  This  pin  is  located  in  the  bracket  T,  with  a  spring  at  the 
back  at  S  and  a  handle  at  It  to  allow  of  its  being  forced  back 
when  the  mandrel -lever  is  to  be  turned. 

When  the  machine  is  in  use  the  work  is  located  and  clamped 
between  the  two  jaws  H  H,  with  the  pointed  end  lying  in  the  slots 
L  and  M  of  the  sleeve  K  and  the  spindle  V  respectively,  and  the 
handle  of  the  forming -mandrel  located  and  held  by  the  pin  T, 
Fig.  384.  The  clutch-lever  is  then  pulled  back  and  the  spindle 
V  and  the  sleeve  K  rotate  while  the  forming-mandrel  remains 
stationary,  thus  twisting  the  wire  around  the  mandrel  to  the 
shape  shown  in  the  half-tone.  The  clutch-lever  is  then  pulled 
out  and  the  machine  is  stopped  when  Z  is  released  and  turned 


INTERCHANGEABLE  MANUFA CTURING. 


329 


toward  the  left,  thus  drawing  out  the  sleeve  and  mandrel,  leav- 
ing the  finished  corkscrew  so  that  it  can  be  removed  by  loosen - 


Fig.  385. 

ing  or  raising  the  upper  jaw  H.  The  mandrel  and  sleeve  are 
then  slid  back  in  position,  another  piece  of  wire  is  located,  and 
the  operations  are  repeated. 

A  SPECIAL   TOOL   FOR   CUTTING   LAEGE  FIBRE- 
WASHERS. 

In  a  shop  in  Brooklyn,  where  they  make  large  embossing 
presses,  the  rollers  of  which  are  made  up  of  fibre-washers  forced 
on  to  machine-steel  shafts,  I  saw  a  tool  for  cutting  the  washers 
from  the  sheets.  This  is  shown  in  Fig.  387,  and  the  manner  of 
using  in  Fig.  388.  In  the  shop  referred  to,  two  sizes  of  washers 
are  used ;  one  size  15  inches  in  diameter  with  4-inch  hole,  and 
the  other  18  inches  in  diameter  with  5 -inch  hole.  The  thickness 
of  the  fibre  board  is  ^-inch. 

As  shown  in  Fig.  387,  the  tool  consists  of  a  1-inch  drill  with 
a  cutter-head  beam  B  let  through  a  slot  as  shown,  and  fastened 


330 


TOOL-MAKING  AND 


by  two  screws.  Cand  D  are  the  cutter-heads,  which  are  finished 
to  a  good  sliding  lit  on  the  beam,  and  /  and  IT  the  cutters,  which 
are  hardened  and  tempered  and  let  into  split  seats  in  the  cutter - 


FiG.  386. 

heads  and  fastened  by  the  screws  G.  The  cutting-tools  are  a 
trifle  less  than  yL-inch  in  thickness  and  are  given  sufficient  back 
and  side  clearance  to  allow  them  to  cut  freely. 

Fig.  388  shows  how  the  tool  is  used.     A  piece  of  l|-inch 
planking  is  fastened  to  the  drill-press  table,  and  the  table  is 


Fig.  387. 


clamped  in  a  central  position.  A  small  pin  forced  into  the 
planking  at  the  right  serves  as  a  gauge  for  locating  the  fibre  be- 
neath the  drill  and  also  to  space  the  washers  evenly.     The  drill- 


INTERCHANGEABLE  MANUFACTURING. 


331 


shank  is  fastened  in  the  chuck  in  the  drill -spindle  and  the  tool  is 
rotated  at  about  forty  turns  per  minute.  The  drill  cuts  first,  and 
as  soon  as  it  has  passed  through  the  fibre  and  entered  the  wood 
the  inside  and  outside  cutters  begin  to  cut.  A  slight  pressure  is 
all  that  is  necessary  to  make  the  tools  cut,  the  shavings  curling 


l"|  OUTSIDE  CUTTER 

\\  INSIDE  CUTTER,!, 

FIBRE 


Fig.  388. 

up  nicely,  and  as  soon  as  they  have  passed  through  the  fibre  a 
quick  raise  on  the  feed -lever  causes  them  to  pull  free  and  clear 
of  the  work.  As  will  be  seen,  the  tool  cuts  the  inside  and  the 
outside  of  the  washer  simultaneously,  and  as  the  insides  are 
used  as  washers  for  smaller-sized  rolls  two  washers  really  are 
produced  at  once. 


AN  UNUSUAL  AND   SPECIAL  JOB  OF  TOOL-MAKING. 

Figs.  389  and  390  show  a  rather  unusual  job  of  tool -making, 
and  Figs.  391  and  392  the  manner  and  means  used  in  its  accom- 
plishment. The  job  in  question  was  the  making  of  a  tap  and  die 
for  cleaning  out  and  "  sizing  "  a  patent  pipe  union,  the  parts  of 
which  were  of  brass  and  were  cast.  The  thread  required  in  the 
union  was  a  lMnch  diameter,  -fe -inch  square  thread,  and  instead 


B    A    E    D  C 


D  C    B         E    D    C 
Fir,.  389. 


of  one  continuous  thread,  five  were  required.  Thus  the  pitch  of 
each  thread  was  If -inch.  This  will  be  understood  from  Fig.  389, 
in  which  the  tap  is  shown  as  finished.     A  is  the  first  thread,  B 


332 


TOOL-MAKING   AND 


the  second,  C  the  third,  D  the  fourth,  and  E  the  fifth.  L  L  are 
the  spiral  flutes,  of  which  there  were  five. 

The  tap  was  made  first.  The  means  used  are  shown  in  Fig. 
391  and  consist  of  a  small  face-plate  fitting  the  lathe-spindle,  a  dog 
and  a  driver.  The  face-plate  had  five  holes  drilled  and  reamed 
at  equal  distances  apart  on  a  radius  true  with  the  live  centre 
of  the  lathe.  This  was  done  on  the  dividing-head  of  the  univer- 
sal milling-machine,  first  indexing  for  five,  and  centring  with  a 
stiff  centre-drill,  then  drilling  and  reaming  to  size.  A  driver  of 
tool  steel  was  then  turned  up  as  shown,  with  a  stem  Q  threaded 
for  the  nut  U,  and  turned  to  fit  snugly  the  reamed  hole  in  the 
face-plate  and  to  shoulder  at  H. 

The  dog  T  was  also  of  tool  steel,  and  was  finished,  as  shown, 
with  a-  broached  hole  to  fit  the  square  on  the  shank  of  the  tap- 


FRONT  VIEW  ACTION 
OF  FACEPLATE    AND 
DRIVER 


FAIL  CENTER 


Q& 


FIG.  391. 


blank  snugly,  so  that  there  would  be  no  lost  motion.  A  set- 
screw  was  also  let  in,  as  shown,  to  insure  the  positive  locating 
and  drive. 

The  manner  in  which  the  tap -blank  was  held  and  driven  on  the 
lathe-centres  when  cutting  the  threads  is  shown  clearly  in  Fig.  391. 
The  first  thread  was  cut  by  locating  the  driver  in  the  first  hole  in 
the  face-plate.  Then  the  second  thread  B  was  cut  and  finished 
by  transferring  the  driver  to  the  next  hole.  Thus  in  succession 
the  entire  five  threads  were  cut  and  the  tap  finished  accurately. 
The  dog  was  not  moved  from  its  position  on  the  end  of  the  blank 
until  the  tap  was  cut.  As  will  be  seen,  the  side  of  the  dog  T 
which  bears  against  the  driver  is  hollowed  out  to  the  radius  of 
the  drive-stem,  thus  giving  a  wide  bearing  surface  and  insuring 
a  positive  drive.     A  piece  of  belt  lacing,  tied  around  the  dog- 


INTERCHANGEABLE  MANTJFA  CI THING. 


333 


stem  and  driver,  prevented  backlash  when  the  tap-blank  was  re- 
volving free.  In  doing  the  cutting  a  tool  accurately  ground  to 
size  and  clearance  was  necessary.  After  being  cut  the  tap  was 
"backed  off"  slightly  and  then  fluted  on  the  milling-machine, 
finishing  the  flutes,  five  in  number,  on  a  spiral,  so  that  the  cut- 
ting-faces of  the  thread  sections  would  be  at  right  angles  with 
the  pitch,  as  shown. 

After  being  hardened,  the  cutting-head  was  ground,  grinding 
the  tap -taper  for  half  its  length.  Not  much  lead  was  necessary 
as  the  tap  was  to  be  used  for  cleaning  and  sizing  only. 

The  manner  in  which  the  die  was  finished  can  be  understood 
from  Fig.  392.     The  die-blank  was  1^  inches  thick  by  3£  inches  in 


Fig.  392. 


diameter.  After  the  outside  had  been  turned  to  the  required  size 
the  die-blank  was  left  on  the  mandrel  on  which  it  had  been 
turned,  and  was  set  np  in  the  centres  of  the  universal  miller. 
A  cutter  was  then  used  to  mill  five  equidistant  semicircular 
grooves  around  the  outside,  as  shown  at  0.  Next,  another  small 
face-plate,  fitting  the  spindle  of  the  lathe  in  which  the  tap  had 
been  cut,  was  bored  and  finished  with  a  seat  at  L  L  for  locating 
the  die-blank  true,  and  with  clearance  at  B  B  for  the  thread- 
tool.  A  hole  was  then  drilled  in  the  face-plate  so  as  to  be  dead 
true  with  the  half-round  grooves  in  the  die-blank,  and  a  Stub 
steel  pin  driven  into  it,  as  shown  at  P.  The  diameter  of  this 
pin  was  exactly  the  same  as  the  grooves  in  the  die-blank.     Thus 


334  TOOL-MAKING   AND 

the  central  locating  of  the  die-blank  on  the  face-plate  was  insured 
by  the  locating-seat  L  L,  and  the  spacing  of  the  threads  by  the 
half-ground  grooves  O  and  the  indexing-pin  P.  The  clamping 
arrangements  require  no  description,  as  the  drawings  show  them 
plainly. 

To  cut  the  threads  the  die-blank  was  located  on  the  face-plate, 
as  shown,  with  the  pin  P  in  the  first  groove  0.  Thus  the  first 
thread  was  cut.  Then  the  clamps  were  removed  and  the  die- 
blank  relocated  at  the  second  groove,  and  the  clamps  retightened 
and  the  second  thread  cut.  These  operations  were  repeated  un- 
til the  entire  five  threads  had  been  finished  to  within  a  shade  of 
the  diameter  of  the  tap.  The  die  was  then  removed  and  sized 
with  the  tap. 

By  reverting  to  Fig.  390  the  reader  will  see  how  the  die  was 
finished.  II II  H II  are  holes  drilled  at  an  angle  with  the  die- 
face,  so  as  to  have  the  cutting-faces  of  the  threads  at  approximately 
right  angles  with  the  pitch.  The  die  was  left  solid  and  hardened, 
and  the  shrinkage  resulting  in  it  allowed  of  the  parts  cleaned 
and  sized  by  the  die  being  an  easy  fit  within  the  parts  finished  by 
the  tap. 

SPECIAL  ENGKAVIXG-  MACHIKE. 

The  machine  represented  herewith  in  Figs.  393  to  396  was  de- 
signed by  the  writer  for  the  special  purpose  of  engraving  moulded 
composition  checks,  which  are  used  for  a  number  of  purposes  in- 
stead of  money,  in  sets  of  exact  duplication ;  this  being  impossi- 
ble by  the  hand  method,  which  was  the  means  used  before  this 
machine  was  designed. 

As  these  check  sets  are  produced  in  large  quantities  and  as 
there  is  always  a  steady  demand  for  the  best  quality,  the  use  of 
the  machine  here  shown  proved  a  great  factor  in  reducing  the 
cost  of  their  production.  Its  use  also  allowed  of  the  attainment 
of  results  in  duplication  which  were  formerly  impossible. 

The  design  and  construction  of  this  machine  is  such  as  to 
allow  of  its  adoption  for  a  multitude  of  other  uses  besides  the 
special  one  for  which  it  was  used.  A  few  of  the  uses  to  which 
it  may  be  adapted  by  mechanical  readers  are :  the  backing  off  of 
small  gear,  ratchet,  and  other  cutters  for  clock  and  watch  work, 


INTERCHANGEABLE  MANVFA  CT UBING. 


335 


the  turning  of  odd-shaped  punches,  wherever  they  are  used  in 
large  numbers,  turning  elliptical  punches  and  dies,  either 
straight  or  taper,  and  the  finishing  of  small  circular  cams  and 
eccentrics.  A  number  of  other  uses  will  suggest  themselves  to 
the  practical  man.  The  writer  has  already  adapted  the  princi- 
ple of  this  machine,  with  slight  modifications,  in  a  new  machine 
to  be  used  exclusively  for  backing  off  cutters  for  watch  and  clock 
pinions. 

As  the  three  views  of  the  machine  show  clearly  its  design  and 
construction  as  well  as  its  use,  we  will  confine  ourselves  to  merely 
pointing  out  its  main  features.     The  construction  of  the  head 

l-A-A 


Fig.  393. 

requires  no  description  whatever,  as  it  is  shown  clearly  in  Fig. 
396.  Reference  being  made  to  the  three  views :  the  machine 
consists  of  the  base  A,  on  which  the  bearings  B  B  for  the  head- 
spindle  and  those  at  C  C  for  the  cam-spindle  are  cast  in  two  legs 
to  which  the  base  is  fastened  and  the  head  and  slide-rest.  In  the 
front-end  view,  Fig.  394,  the  check  is  held  in  the  spring-chuck  G 
and  the  tool  U  set  to  as  shown.  The  gear  Ron  the  cam-spindle 
is  the  same  size  as  the  one  at  Q  on  the  head-spindle  and  is  driven 
by  the  intermediate  gear  J.  The  cam  B  is  of  tool  steel  and  is 
hardened  and  lapped  to  a  smooth  finish.  The  engaging-stud  T 
is  also  of  tool  steel  and  is  driven  into  the  tool-slide  Q  as  shown, 


336 


TOOL-MAKING   AND 


and  the  pointed  end  rests  against  the  cam  B.  The  spring  B  B 
at  the  front  is  of  sufficient  strength  to  keep  the  engaging-stud  T 
tightly  against  the  cam  face. 

When  the  machine  is  in  use,  a  check  is  held  in  the  spring- 
chuck  G  and  the  tool   U  set  as  shown.     The  machine  is  then 


Fig.  394. 


started  and  the  tool  fed  up  to  the  work  by  turning  the  cross-slide 
handle  Z.  The  cam  B  revolves  at  the  same  speed  as  the  work 
and  the  slide  W  is  moved  in  and  out  accordingly,  the  tool  pro- 


FiG.  395. 


during  the  results  shown.     As  everything  else  can  be  seen  and 

understood  from  the  drawings  no  further  description  is  required. 

In  Figs.  397-403  are  shown  seven  samples  of  checks  which 

were  engraved  in  this  machine.     For  the  one  shown  at  A  a  tool 


INTERCHANGEABLE  MANUFACTURING. 


337 


with  four  points  was  required ;  for  the  one  shown  at  £  a  tool 
with  three  points ;  while  for  C  D  E  and  G  tools  with  two  points 


_,CL09E0 

1SPRING  CHUCK 


FIG.  396. 


were  used,  and  for  F  one  with  one  point.     For  each  different 
design  a  special  cam  was  made.     With  the  machine  a  boy 


Fig.  397. 


Fig.  399. 


FIG.  400. 


FIG.  401. 


Fig.  402. 


FIG.  403. 


turned  out  four  checks  a  minute,  while  an  engraver  working  by 
hand  could  only  turn  out  one  every  minute. 


SPECIAL   CAM-MILLING  MACHINE. 

Fig.  404  shows  a  plan  of  a  special  cam -milling  machine  built 
for  milling  certain  cams  used  on  a  printing-press.  E  is  the  cam 
as  milled.  It  is  in  the  form  of  a  stepped  cone  and  is  fastened  to 
the  spindle  B  by  the  nut  F.  G  G  are  the  standards  in  which  the 
spindle  B  is  rotated  and  reciprocated  endwise  by  means  of  the 
gear  C  and  the  master-cams  A  A.  D  D  are  two  lugs  projecting 
up  from  the  base  of  the  machine  in  which  are  turn  rollers  which 
contact  with  the  cam  surfaces. 

K  K  are  the  standards  for  the  milling-spindle,  L  a  cone  pulley 

22 


338 


TOOL-MAKING   AND 


driven  by  belt,  M  a  worm  which  turns  a  worm-gear  on  spindle 
N,  H  the  milling-cutter,   I  a  draw-in  spriug-chuck,  and  •/the 


FIG.  404. 


driving-spindle.     T  is  the  hand-wheel  for  feeding  in  the  cutter 
H.     The  pinion  0  on  the  worm-gear  shaft  N  drives  gear  Q,  and 


Fig.  405. 

pinion  R  drives  the  large  gear  G  on  the  cam-spindle.  Thus  the 
milling-cutter  is  rotated  at  a  high  speed  and  the  work  E  very 
slowly. 

CHUCK  FOR  TURNING   ECCENTRIC   RINGS. 

Fig.  405  shows  a  chuck  used  for  turning  eccentric  brass  rings 
of  the  shape  and  section  shown  at  A  in  the  engraving.     They 


INTERCHANGEABLE  MANUFACTURING.  339 

were  to  be  bored  out,  faced  on  both  sides  and  turned  on  the 
periphery,  all  dimensions  being  made  to  gauge  so  that  the  pieces 
would  interchange.  In  order  to  turn  out  the  work  at  a  profit  it 
was  necessary  to  design  and  build  a  few  fixtures  for  the  handling 
of  the  work.  Two  chucks  were  made  for  this  purpose.  The 
first,  which  held  the  ring  while  the  eccentric  hole  was  being  bored 
and  one  side  faced,  was  of  no  special  interest.  After  this  opera- 
tion the  keywayat  -5  was  machined  with  the  aid  of  a  simple  slot- 
ting fixture. 

The  chuck  that  was  employed  for  the  last  operation,  that  of 
turning  the  periphery  and  facing  the  remaining  side,  possesses 
several  features  of  general  interest  that  may  be  adapted  to  other 
work  of  a  similar  nature.  This  chuck  is  shown  in  Fig.  405  hold- 
ing one  of  the  rings  in  position  to  be  operated  upon.  The  body 
of  the  chuck  C  was  threaded  to  screw  on  to  the  spindle  of  the 
lathe,  and  carried  on  its  face  three  expanding  and  contracting 
segments  for  truing  and  holding  the  ring,  one  of  them  being  pro- 
vided with  a  key  which  fitted  the  keyway  B  for  locating  and 
driving  the  ring.  These  segments  were  held  in  place  on  the  face- 
plate by  three  shoulder-screws  D  D  D  which  passed  through 
radial  slots,  thereby  allowing  the  segments  an  in-and-out  move- 
ment across  the  face  of  the  chuck.  This  expanding  movement 
was  imparted  to  the  segments  by  means  of  the  knurled-head  ex- 
panding-screw  E,  which  was  tapered  slightly  so  that  the  ten- 
dency when  they  were  tightened  or  expanded  would  be  to  force 
the  work  against  the  face-plate.  The  clamping  surfaces  were 
eased  off  so  that  only  about  an  inch  of  each  would  bind  against 
the  work. 

The  manner  in  which  the  chuck  was  used  and  the  work  ma- 
chined was  as  follows:  The  stud  E  being  screwed  outward  by 
grasping  its  knurled  head,  the  segments  were  contracted.  Then 
the  ring  was  located  against  the  face-plate  with  the  key  in  the 
segment  fitting  the  keyway  B.  The  expanding -stud  was  then 
screwed  in  and  the  segments  in  expanding  forced  the  work  tightly 
against  the  face-plate  and  held  it  securely.  It  was  then  a  simple 
matter  to  turn  the  periphery  to  the  required  diameter  and  face 
the  side,  after  which  the  segments  were  contracted  by  unscrew- 
ing the  expander,  the  finished  piece  was  removed,  and  another 


340 


TOOL-MAKING   AND 


located  ready  for  machining.  As  will  be  understood,  the  ma- 
chining of  the  rings  with  the  usual  means  handy  around  the  shop 
would  have  been  difficult  and  would  have  consumed  much  time ; 
while  by  this  method  there  was  no  time  lost  and  the  complete  in- 
terchangeability  of  the  rings  when  finished  was  guaranteed.  It 
was  surprising  how  easily  and  rapidly  the  rings  were  located  and 
removed  and  how  tightly  they  were  held.  As  the  brass  castings 
from  which  the  rings  were  finished  were  not  of  the  best  quality, 
a  cut  of  considerable  depth  had  to  be  taken,  thus  putting  con- 
siderable strain  on  the  segments. 

CHUCKING  FIXTURE  FOE   ECCENTRIC    STRAPS. 

While  none  of  the  tools  shown  in  the  following  are  of  very 
unusual  construction,  they  are  of  interest  because  of  their  sim- 
plicity and  their  value  in  producing  rapidly  and  interchangeably 
the  required  parts. 

The  first  fixture  is  shown  in  two  views  in  Figs.  406  and  407. 
It  is  used  in  the  boring  and  tapping  of  the  hole  A  in  the  eccen- 


1 

-"1 

n 
!    L~ 

!  I~~ 

rr~n 

l=S= 

ft! 

1 

Fig.  406. 


Fig.  407. 


trie  strap  B.  The  piece  is  of  cast-iron,  and  the  operations  per- 
formed previous  to  the  one  mentioned  are  the  milling  of  the 
faces  of  the  two  parts  of  the  strap,  the  drilling  and  tapping  of 
the  two  holes  in  the  lugs  for  cam -screws,  the  boring  of  the  4|--inch 
hole,  and  the  facing  of  the  two  sides.  The  hole  is  bored  and  the 
two  sides  faced  at  the  one  handling  by  strapping  the  work  on 


INTERCHANGEABLE  MANUFA GTURING. 


341 


the  lathe  face-plate  so  that  the  lugs  rest  on  parallels  which  are 
thick  enough  to  allow  of  using  a  "hook"  tool  for  finishing  the 
side  nearest  the  face-plate. 

The  fixture  for  boring  and  tapping  the  hole  A  as  shown  in 
Figs.  406  and  407  is  very  simple  and  requires  but  little  descrip- 
tion. It  consists  of  an  angle-iron,  which  is  bolted  to  the  lathe 
face-plate;  a  "locator,"  and  two  clamps.  The  "locator"  and  its 
use  are  shown  in  the  plan  view.  It  is  fastened  to  one  face  of  the 
angle-iron  by  means  of  two  flat-head  screws  so  that  the  strap  B 
will  be  located  central  and  true ;  the  planed  surface  by  which  the 
piece  B  is  joined  to  the  other  section  resting  squarely  against 
the  face-plate.  As  will  be  seen,  the  use  of  this  fixture  insures 
the  locating  and  finishing  of  the  hole  A  centrally,  and  in  lire 
with  the  large  hole  in  the  strap. 

TWO   NOSE-CHUCKS   FOE   ECCENTEIC   CAMS. 

In  Figs.  408  and  409  we  have  two  views  of  a  chuck  used  for 
the  first  operation  on  an  eccentric  cam.  It  is  of  cast-iron,  bored 
and  threaded  at  the  back,  and  bored  eccentric  at  the  front  for 


m 


M 


Fig.  408. 

the  stem  I  of  the  cam.  This  eccentric  hole  was  laid  out  With  the 
height-gauge  and  "buttoned,"  and  then  indicated  on  the  lathe 
face-plate  and  bored.  A  pin  J"  locates  the  cam  j>roperly  and  as- 
sists in  driving  it  while  the  surfaces  K  and  L  are  being  ma- 
chined. Two  set-screws  equipped  with  brass  ends  are  used  at  M 
to  secure  the  stem  in  the  chuck. 

The  next  operation  on  the  cams  is  the  milling  to  size  of  the 


342 


TOOL-MAKING   AND 


portion  indicated  at  N.  For  this  a  simple  little  device  (not 
shown)  in  the  form  of  an  angle -iron  with  a  seat  upon  which  to 
clamp  the  machined  portion  of  the  cam  is  used. 

For  the  third  operation,  which  is  the  last,  the  chuck  shown  in 
Fig.  410  is  used.     As  will  be  seen,  this  is  of  much  the  same  de- 


FlG.  410. 

sign  as  the  other,  except  that  it  is  equipped  with  a  "  locator " 
which  fits  the  milled  channel  N.  Two  set-screws  fasten  the  work 
in  the  chuck. 

-  It  is  obvious  that  with  these  two  chucks  the  production  of 
cams  that  are  interchangeable  is  not  difficult,  and  at  the  same 
time  it  is  possible  to  machine  them  rapidly. 


FIXTUEE  FOE  CHUCKING   GASOLINE-ENGINE 
CYLINDEES. 

The  chuck  shown  in  Figs.  411  to  413  contains  some  points  of 
interest  that  may  be  adapted  to  the  rapid  production  of  any  work 
of  a  character  similar  to  the  pieces  for  which  the  fixture  was  de- 
signed. The  casting  for  holding  which  this  chuck  was  made 
was,  as  will  be  seen,  of  rather  unusual  shape.  It  formed  a  triple 
cylinder  for  a  high-speed  automobile  engine  which  was  being 
manufactured  in  large  numbers.  It  had  three  cylinders  B  B  B, 
which  were  required  to  be  bored  out  and  reamed  to  size  at  C, 
turned  on  the  outside  at  E,  and  counterbored  and  tapped  for 
plugs  at  D.  The  portion  indicated  by  the  letter  A  was  the  hub. 
The  centres  of  all  three  cylinders  had  to  be  on  the  same  plane 
and  spaced  so  as  to  form  exactly  the  same  angle  with  each  other. 


INTEBGHANGEABLE  MANUFA  CTUBING. 


343 


The  construction  and  use  of  the  chuck  will  be  seen  by  refer- 
ence to  the  three  views  shown  in  the  illustration.  G  is  a  face- 
plate, turned  and  finished  to  screw  on  to  the  lathe  spindle  and 
channeled  down  the  face  to  allow  of  locating  the  angle-plate  H, 
which  was  fastened  to  it  by  the  cap -screws  A"  A  A.  The  hub  of 
the  casting  was  first  held  in  another  chuck  and  bored  out  on  the 
inside  and  finished  on  the  outside  to  gauge.  This  preliminary 
work  formed  the  basis  for  the  accurate  accomplishment  of  all  the 
succeeding  operations.      The  work  was  then  located  centrally 


FIG.  411. 


on  a  boss  F  formed  upon  the  bracket  H  so  that  the  three  cylin- 
ders would  come  approximately  central.  For  clamping,  the  three 
straps  N  N  N  were  used ;  while  the  indexing  was  accomplished 
by  plug  A,  Fig.  412,  whose  locating  part  was  hardened  and 
ground  to  fit  the  finished  bore  of  the  cylinder,  and  also  the 
reamed  hole  in  the  lug  J. 

When  using  the  chuck,  a  casting  was  first  clamped  somewhat 
loosely  upon  the  angle-plate  H,  being  located  centrally  by  the 
stud  F.  A  plug,  which  for  a  distance  along  its  length  fitted 
the  reamed  hole  in  the  lug  J  and  for  the  rest  of  its  length  fitted 


344 


TOOL-MAKING  AND 


the  cored  holes  in  the  cylinders  loosely,  was  inserted,  through  the 
lug,  into  one  of  the  cylinders.     The  clamps  were  then  tightened 


Fig.  412. 


and  the  machining  proceeded.     First  the  outside  of  the  cylinder 
was  turned  at  E  E  to  gauge,  after  which  the  steady  rest  was 


FIG.  413. 


brought  up  and  adjusted  so  that  the  finished  portion  ran  true 
within  it.     This  was  followed  by  the  boring  and  reaming,  which 


INTERCHANGEABLE  MANUFACTURING. 


345 


was  done  by  first  using  a  bar  with  an  inserted  cutter,  then  a 
shell-rose  reamer,  and*  finally  a  one-bladed  reamer  for  finishing. 
After  reaming,  the  counterboring  and  tapping  were  done.  Now 
the  clamps  were  loosened  and  slid  back,  the  work  removed  from 
the  angle-plate — the  temporary  plug  having,  of  course,  been  first 
removed — and  the  casting  relocated  with  the  finishing-cylinder 
in  line  with  the  lug  J.  The  plug  K  was  then  inserted,  through 
the  lug,  into  this  cylinder,  which  it  fitted  perfectly.  The  set- 
screw  M  was  tightened,  thereby  holding  the  plug  securely  in 
place,  after  which  the  clamps  were  secured  and  the  second  cylin- 
der was  bored,  reamed,  counterbored,  and  tapped  as  had  been 
done  with  the  first.  After  this  the  same  method  of  procedure 
was  followed  for  finishing  the  third,  or  remaining,  cylinder. 


SPECIAL   MILLING-  AND   DBILLING-JIGS. 

Fig.  414  shows  a  casting  which  formed  part  of  a  clutch  for  a 
perforating  machine.  The  jigs  shown  in  Figs.  415,  416,  417,  and 
418  were  used  in  its  production.  The  castings  were  4^  inches 
in  diameter  by  3^  inches  long,  with  a  cored  hole  in  the  centre. 


Fig.  414. 

The  work  to  be  done  consisted,  first,  of  boring  and  reaming  the 
hole  A  A  to  2  inches,  facing  both  sides,  turning  the  outside,  and 
cutting  in  the  groove  E  E.  For  this  plain  lathe  no  fixtures  were 
necessary.  The  further  operations  required  were:  Boring  the 
hole  B  for  the  sliding  clutch-pin,  milling  the  slot  D  D  for  the 
feather  C,  and  drilling  the  hole  F. 

For  drilling  the  hole  B  the  jig  Fig.  415  was  used.  The  cast- 
iron  body  or  base  is  machined  on  the  bottom  to  bolt  on  to  the 
table  of  the  drill -press.  This  body  casting  has  a  stem  projecting 
up  from  the  centre  which  is  turned  to  fit  the  hole  A  A  in  the 


346 


TOOL-MAKING   AND 


work,  and  is  tapped  at  the  top  to  admit  the  bushing-plate  clamp- 
ing-screws. There  is  a  machined  seat  for  the  work  to  locate  On. 
The  body  of  each  clamping-screw  enters  the  locatiug-stem  for 
a  certain  distance  to  insure  the  locating  of  the  centre  of  the 
hole  B. 

The  milling  of  the  slot  D  D  in  the  casting  and  the  drilling 
of  the  hole  F  were  accomplished  by  the  jig  shown  in  Figs.  416, 

mi 


_j 


i    i 


JU 


_L 


. .  ■. 


c 


FIG.  415. 


417,  and  418 ;  Fig.  416  showing  it  as  used  for  the  milling  of  the 
slot,  and  Figs.  417  and  418  when  drilling  the  hole  F. 

The  fixture  consists  of  an  angle-plate  with  a  central  locating- 
stud  fitting  the  centre  hole  of  the  work.     This  stud  is  tapped  for 


Front  or  Face  View 


FIG.  416. 

the  fastening -screw.  To  locate  the  work  on  the  jig  so  that  the 
slot  D  D  when  milled  will  be  properly  located,  the  hole  B  in  the 
work  is  utilized,  a  steel  pin  in  the  jig  fitting  it.  This  pin  is 
made  to  fit  the  hole  in  the  work  and  two  holes  in  the  fixture  easily 
to  allow  of  its  removal  and  re-use  in  locating  the  work  in  position 
for  drilling  the  hole  F.     To  expedite  the  locating  and  fastening 


INTERCHANGEABLE  MANUFA  CTV1UNG. 


347 


of  the  work  on  the  fixture  and  its  removal  when  milled  a  clamp- 
ing-washer with  a  section  cut  out  is  used,  thus  allowing  of  merely 


)- 


Fir.  417. 

loosening  the  screw  and  slipping  out  the  washer  when  removing 
the  work.  When  in  use  the  fixture  is  located  on  the  miller-table 
and  held  by  two  bolts,  the  tongue  fitting  the  central  groove  of 
the  table. 

The  manner  in  which  the  hole  F  is  drilled  is  clearly  indicated 


Fig.  418. 


by  Figs.  417  and  418.     As  will  be  seen,  all  that  is  necessary  to 
allow  of  using  the  fixture  for  this  operation  is  the  locating  of  the 


348 


TOOL-MAKING  AND 


stud  in  B  and  the  locating  and  fastening  of  the  bushing-plate 
/  on  the  top  of  the  body  casting.  G  G  are  dowels,  H  a  cap- 
screw,  and  J  a  bushing.  As  the  hole  has  only  to  run  into  the 
centre  bole  A  of  the  work,  the  presence  of  the  screw  W  does  not 
interfere  with  the  drilling.  Although  the  fixtures  are  very 
simple  and  inexpensive  they  are  great  labor  savers. 

A   SET   OF   JIGS   FOE   MILLING  AND  DRILLING. 

In  Fig.  419  we  have  three  views  of  a  cast-iron  punch-head 
used  on  gang  eyelet-perforating  machines.  These  punch-heads 
are  required  to  be  machined  accurately  so  as  to  be  interchange- 
able, and  are  handled  during  the  course  of  manufacture  entirely 
by  jigs.  While  the  work  done  by  the  use  of  these  jigs  is  very 
accurate  and  is  accomplished  rapidly,  none  of  them  are  intricate 
or  expensive.     The  piece  shown  is  about  ten  inches  long  over  all. 


Gib 
Side  |^« 

M 


D 


©  v 


Fig.  419. 

The  punch-head  consists  (not  counting  screws)  of  four  parts: 
The  head  proper,  of  cast-iron;  the  back-plate  V,  of  machine 
steel ;  the  punch-key  I,  of  brass ;  and  the  gib  at  C,  of  machine 
steel.  Leaving  the  smaller  parts,  we  will  take  up  the  machining 
of  the  head  proper. 

The  work  required  to  be  done  on  the  punch-head  consists  of 
milling  all  sides  square  and  true,  milling  the  dovetail  B  B  and 
the  gib-way  G,  milling  the  angular-formed  face  D  D,  drilling 
and  reaming  the  long  central  hole  E  E,  drilling  four  holes  H  for 
fastening  the  back-plate,  two  holes  fou  fastening  the  brass  key, 
one  hole  for  the  gib-tightening  screw  F  and  another  clearance- 
hole  for  the  gib -pin  G. 


INTERCHANGEABLE  MANUFACTURING. 


349 


The  castings  for  the  heads  before  machining  were  square  all 
over  except  for  the  dovetailed  and  gib  surfaces,  which  were 
roughly  cast. 

The  first  operation  was  accomplished  ou  a  large  milling-ma- 
chine by  means  of  a  supply  fixture,  and  a  large  inserted  tooth- 
milling  cutter  handling  ten  castings  at  a  time.  This  fixture  is 
not  illustrated. 

For  milling  the  dovetail  and  gib- way  the  jig  Fig.  420  was 
used.     This  accommodated  eight  castings.     The  work  is  located 


Fig.  420. 


on  a  machined  seat.  P  P  are  the  side-locatings,  L  L  the  lugs  for 
the  side-fastening  screws,  and  A  the  projection  in  which  the  end- 
fastening  screws  are  located.     With  this  jig  the  vertical  milling 


The  Wcrfc 


Fig.  421. 


Fig.  422. 


attachment  was  used.  First  the  dovetailed  slideway  was  ma- 
chined with  an  angular  cutter,  taking  two  cuts,  one  at  each  side ; 
then  the  gib-way  -C  was  machined  by  substituting  a  suitable  cut- 
ter for  the  angular  one.  As  all  the  surfaces  of  the  castings  were 
perfectly  square  and  to  size,  the  milling  in  this  operation  was 
done  very  rapidly. 


350 


TOOL-MAKING    AND 


The  milling  of  the  inclined  formed  face  D  D  of  the  castings 
was  done  by  handling  one  casting  at  a  time  in  the  jig  Figs.  421 
and  422.  The  amount  of  material  removed  in  this  operation  is 
indicated  by  the  dotted  lines.  A  large  formed  milling-cntter  was 
used  for  this  work. 

Operation  fourth  was  the  drilling  of  all  the  holes  in  the  head 
casting.  This  drilling  was  done  before  milling  the  keyway  for 
the  brass  key,  because  the  long  central  hole  H  H  had  to  be  per- 
fectly straight  and  reamed  to  size. 

Fig.  423  is  a  plan  partly  in  section  of  the  jig.  It  is  of  the 
box  type  with  cast  legs  L  on  four  sides.     The  work  is  located  by 


Fig.  423. 

means  of  the  dovetailed  locator  N  N  on  a  machined  seat  in  the 
bottom  of  the  jig,  and  is  secured  by  means  of  a  swinging  strap, 
not  shown,  hinged  at  Xand  fastened  at  Z  by  a  thumb-screw. 
The  locator  N  N  is  of  machine  steel,  fastened  to  the  inside  of  the 
jig  side  by  two  dowels  C.  The  bushings  for  drilling  the  long 
hole  are  removable.  They  are  notched  at  the  side  for  the 
knurled-head  locating-pins  R,  which  prevent  them  from  turning 
or  falling  out.  The  hole  II H  is  drilled  from  both  ends,  half 
way  from  each.  When  reaming,  the  two-drill  bushings  are  re- 
placed by  others.  One  at  the  bottom  fits  the  reamer,  while  the 
upper  one  fits  the  stem.  In  reaming  this  hole  a  shell  reamer  re- 
versed is  used,  so  that  the  cutting-end  is  upward  and  the  hole  is 
reamed  from  the  bottom. 

For  milling  the  cross-slot  or  keyway,  the  jig  shown  in  Fig. 
424  was  used.     This  was  made  to  hold  a  number  of  castings  at 


INTERCHANGEABLE  MA  NUFA  CTUBING. 


351 


ouce.  The  work  is  located  and  fastened  positively  and  with  ease, 
and  its  removal  when  finished  is  quickly  accomplished.  The 
clamp  shown  at  the  front  end  is  so  made  as  to  allow  of  locating 


Fig.  424. 


it  quickly  by  means  of  the  small  latch  P  which  is  hinged  in  the 
clamp  at  K.     By  simply  pressing  back  the  handle  of  this  latch 
the  clamp  is  released  and  may  be 
slid  off. 

By  reverting  to  Fig.  419  the 
machining  required  for  the  small 
parts  will  be  understood.  First, 
we  have  the  back -plate  V.  This 
is  of  machine  steel  and  is  first 
milled  and  squared  all  over,  the 
milling  of  the  formed  edge  to  co- 
incide with  the  formed  face  D  D 
of  the  imuch-head  being  done  after 
the  drilling  of  the  four  screw- 
holes.  Then  we  have  the  brass 
"  key. "  This  is  cut  from  the  bar 
and  cleaned  up  to  size.  The  drill- 
ing of  the  two  holes  It  in  the  brass 
key  and  the  four  J  in  the  back- 
plate  are  all  done  in  the  one  drill- 
ing-jig, Fig.  425.  The  jig  is  made 
to  accommodate  a  plate  at  one 
end  and  a  brass  key  at  the  other. 
The  body  casting  is  machined  so 
as  to  leave  locating-seats  for  the 
work  and  with  a  channel  across 
it  for  the  piece  0  against  which  the  work  locates.  The  bush- 
ing-plate is  fastened    to  the  body   by   four  flat-head   screws. 


Fig.  425. 


352 


TOOL-MAKING   AND 


S  S  8  S  are  the  plate-drill  bushings  and  T  T  the  key-drill  bush- 
ings. MM  are  the  jig  legs  cast  on. the  body.  Q  and  R  are  two 
screws  for  fastening  the  work  on  and  against  the  locating  sur- 
faces. The  work  is  slipped  in  at  the  ends ;  then  the  screws  are 
tightened  and  the  holes  are  drilled. 

The  remaining  piece  shown  in  Fig.  419  is  the  gib.  This  has 
a  pin  which  is  grooved  out  at  one  side  to  coincide  with  the  taper- 
point  of  the  gib-screw  F.  When  the  screw  is  tightened  it  forces 
the  gib  in  and  thus  clamps  the  head  in  position  on  the  perfo rat- 
ing-machine. This  gib  is  of  machine  steel  and  is  milled  to  size 
in  the  miller-vise,  an  angular  cutter  being  used  to  taper  the 
edge.  For  drilling  the  hole  for  the  pin  L  a  simple  little  slip-jig 
is  used. 

The  tools  shown  possess  no  novel  features,  nor  are  they  of  in- 
tricate construction.  However,  they  are  interesting  and  should 
prove  suggestive  for  other  work,  as  they  illustrate  how  accurate 
repetition  work  may  be  done  rapidly  and  cheaply  if  some  thought 
is  given  to  the  devising  of  simple  and  inexpensive  tools. 


FACING   AND   COUNTEEBOEING   LARGE  SPIDEE 
CASTINGS   IN   THE  DEILL-PEESS. 

In  a  shop  where  paint-mixing  machines  are  built  the  writer 
came  across  a  method  of  facing  and  counterboring  large  castings 


Fig.  426. 


in  the  drill-press  which  may  prove  suggestive  to  readers  for  the 
machining  of  other  work  in  a  like  manner.  An  idea  of  the  shape 
and  size  of  the  castings  may  be  gained  from  Fig.  426,  in  which  is 


INTERCHANGEABLE  MANUFA CTURING. 


353 


shown  the  nature  of  the  work  to  be  done.  As  will  be  seen,  the 
casting  has  two  hubs  which  are  required  to  be  bored  to  a  finished 
diameter  of  five  inches,  then  faced  at  A  A,  B  B,  C  C,  and  I)  D 
respectively,  and,  lastly,  counterbored  at  F  F  to  a  depth  of  one 
inch  and  a  diameter  of  seven  inches.  It  is  at  once  obvious  that 
the  large  drill -press  which  is  equipped  with  a  floor  base  is  the 
proper  machine  for  the  work,  and  that  it  would  be  very  difficult 
to  do  the  work  in  any  other  machine. 

The  boring  to  a  finish  of  the  cored  holes  in  the  hubs  presented 
no  unusual  difficulties;  a  large  boring-bar  of  approved  construc- 
tion being  used  and  the  projecting  end  allowed  to  run  in  a  bush- 
ing bolted  to  the  floor  base  of  the  drill,  to  which  the  work  was 


Fig.  427. 

strapped.  To  accomplish  the  facing  of  the  four  hub  faces  and 
the  counterboring  of  the  seat  in  an  expeditious  and  accurate 
manner,  however,  required  other  means  than  those  used  for  the 
boring.  It  was  for  this  work  that  the  special  facing  and 
counterboring  tool  illustrated  in  Fig.  427  was  used. 

As  will  be  seen,  the  special  tool  consists  of  the  regulation  bar, 
turned  taper  at  one  end  to  fit  the  drill-press  spindle,  and  rounded 
at  the  other  to  enter  easily  the  supporting  bashing  on  the  base 
of  the  press.  This  bar  has  five  holes  let  though  it  to  accommo- 
date the  boring-head.  The  holes  are  indicated  in  the  engravings 
by  letters  C  I)  E  and  F  respectively.  Three  holes  are  for  the 
cutter-bar  and  the  other  two  are  tapj)ed  holes  for  the  feed-screw 
G.  In  the  cutter-head,  H  is  tie  bar,  0  the  "  goose-neck ;J  cut- 
ting-tool, a  seat  for  which  is  provided  in  the  cutter-clamps  M  at 
23 


354  TOOL-MAKING. 

either  side  of  the  centre  as  the  taking  of  under  and  upper  cuts 
necessitates.  I  is  the  connecting  strap  between  the  cutter-bar 
and  the  feed-screw,  J  the  bar-fastening  nut ;  G  the  feed-screw 
and  -ST  the  hand  knob.  JV"is  a  cap-screw  used  for  fastening  the 
cutter  and  cutter-straps  to  the  cutter-bar. 

In  using  this  tool  the  bar  was  projected  down  through  the 
hubs  of  the  casting  until  the  end  ran  in  the  supporting  bushing 
at  the  base.  The  cutter-head  was  then  in  the  position  shown  in 
Fig.  427.  First  the  surface  A  was  faced,  the  feed-screw  being 
turned  a  little  by  hand  at  each  revolution— the  large  opening- 
making  this  an  easy  matter.  Next  the  seat  F  F  was  bored  and 
finished  in  the  same  manner,  feeding  the  spindle  of  the  drill 
down  for  depth  and  the  feed-screw  of  the  cutting-head  for  diam- 
eter. After  this  the  under  face  of  the  upper  hub  was  faced  by 
removing  the  cutter-head  entirely;  feeding  the  spindle  down- 
ward until  the  upper  three  holes  in  the  bar  were  clear  of  the 
under  face  of  the  upper  hub;  then  relocating  the  cutter-head 
with  the  feed-screw  in  the  same  hole  as  it  occupied  in  the  first 
instance;  but  with  the  cutter-bar  in  the  upper  hole  C.  Thus 
the  cutter-bar  was  merely  reversed  and  the  facing  of  the  under 
side  of  the  hub  accomplished  by  feeding  the  spindle  up  instead 
of  down.  The  two  faces  of  the  lower  hub  were  faced  in  the 
same  manner,  the  cutter-head  being  removed  and  reversed  as 
required. 


CHAPTER  XXIII. 

Special  Machines  for  Accurate  Work  on  Dies ;    * 
Their  Use. 

PROGRESS   MADE   IlsT   THE   USE   OF   POWER- 
PRESSES. 

It  must  be  gratifying  to  mechanics  who  are  interested  in  the 
cheap  and  accurate  production  of  metal  parts  to  note  the  won- 
derful progress  that  has  been  made  in  the  use  of  the  power-press 
during  the  last  few  years.  In  fact,  the  time  has  arrived  when 
this  modern  machine  has  demonstrated  its  efficiency,  when  used 
in  conjunction  with  suitable  dies  and  fixtures,  for  producing 
parts  of  steel,  iron,  and  other  metals  at  a  lower  cost  to  the  manu- 
facturers and  to  a  finer  degree  of  interchangeability  than  it  has- 
heretofore  been  possible  to  attain  by  other  means. 

Where  the  power-press  has  been  adopted  for  the  production 
of  metal  parts,  and  where  the  full  value  of  dies  is  understood 
and  appreciated,  the  machines  in  which  they  are  used  have  be- 
come as  important  factors  in  production  as  any  of  the  other 
machine  tools  in  general  use.  The  only  reason  for  their  non- 
adaptation  in  other  establishments,  is  that  their  use  is  not  under- 
stood. There  are  a  great  number  of  shops,  both  large  and  small, 
in  which  duplicate  small  parts  of  standard  shapes  and  sizes  are 
being  constantly  made,  by  milling,  drilling,  filing,  or  other 
means,  that  could  be  produced  at  a  greatly  reduced  cost  and  to  a 
higher  degree  of  accuracy  by  means  of  suitable  dies  iu  the  foot- 
or  power-press.  In  such  shops,  the  use  of  the  product  of  dies, 
that  is,  using  sheet-metal  blanks  instead  of  castings  where  prac- 
ticable, would  cause  the  people  who  are  responsible  for  results  in 
such  shops  to  first  open  their  eyes  and  later  to  double  their  pro- 
duction and  profits. 

355 


556 


TOOL-MAKING  AND 


HAND-FINISHING   VS.    MACHINE-FINISHING   OF 

DIES. 

While  numbers  of  special  machines  and  devices  have  been 
invented  for  the  making  of  all  kinds  of  other  tools,  hand-work, 
to  a  greater  or  less  degree,  has  been  depended  upon  for  the  mak- 
ing of  dies,  from  the  simple  blanking  type  to  combinations  of 
the  tools.  The  advent  of  the  vertical  attachment  for  the  univer- 
sal milling-machine  helped  some ;  but  what  was  wanted  was  a 
machine  which  would  do  the  work  which  it  was  then  only  possi- 
ble to  accomplish  by  the  hand  of  a  skilled  mechanic  with  a  file. 
Thus,  to  a  certain  extent,  the  use  of  dies  has  been  prevented  by 
the  expense  which  would  be  incurred  in  the  making  of  them. 
This  excuse,  however,  is  now  no  longer  operative,  for  there  are 


FIG.  428. 

now  machines  which  will  do  the  work  on  dies  formerly  only  pos- 
sible by  hand  labor.  I  refer  to  the  various  die-shaping  and  mill- 
ing-machines which  are  now  on  the  market. 

The  value  of  these  machines  to  all  concerns  in  which  many 
dies  are  made  may  be  judged  from  Fig.  42S,  in  which  are  shown 
a  number  of  dies  of  different  types  which  were  machined  and 
finished,  up  to  the  point  of  hardeniug,  by  the  use  of  a  die-mill- 
ing machine.  Every  die-maker  knows  the  skill  necessary  for 
finishing  such  dies  by  hand,  especially  in  giving  the  proper  or 


INTERCHANGEABLE  MANUFACTURING.         357 

required  degree  of  clearance  all  the  way  through.  By  the  use 
of  machines  of  the  type  mentioned  above,  this  can  be  accom- 
plished with  ease ;  and  dies  which  are  required  to  be  straight,  or 
tapered  slightly  inward,  as  is  necessary  in  burnishing-dies,  may 
be  finished  with  no  more  trouble  than  would  be  involved  in  the 
finishing  of  a  die  with  excess  clearance. 

USE   OF   DIE-MILLING   MACHINES. 

The  die-milling  machine  may  be  used  for  roughing  out  and 
finishing,  to  within  a  thousandth  of  an  iuch  or  so  of  the  templet 
lines,  any  kind  of  blanking-,  trimming-,  or  pnnching-dies,  such  as 
are  required  to  produce  silverware,  jewelry,  bicycle  parts,  drop- 
forgings,  typewriter  parts,  sewing-machine  parts,  etc. 

A  type  of  die-milling  machine  now  in  use  in  a  number  of  die- 
shops  is  so  constructed  that  the  frame  of  the  machine  is  sup- 
ported on  trunnions,  or  gudgeons,  which  hold  it  in  any  desired 
positiou,  so  that  the  operator  may  have  the  best  possible  light  on 
the  surface  of  the  work.  The  spindle  is  perpendicular  to  the 
machine  face  and  is  adjustable.  When  arranged  for  milling 
blanking-dies  the  cutter  projects  through  an  opening  in  the 
chuck  in  which  the  work  is  clamped,  and  is  straight  or  tapered 
to  suit  the  amount  of  clearance  required  in  the  die.  When  such 
machines  are  used  it  is  only  necessary  to  drill  one  hole  through 
the  die-blank,  and  the  cutter,  starting  in  this  hole  and  following 
the  outline  of  the  templet,  removes  the  entire  centre  in  a  single 
piece.  The  chuck,  or  work-holder,  on  such  machines  is  moved 
in  either  direction  by  means  of  two  slides  at  right  angles  to  each 
other  and,  by  the  use  of  hand-wheels  on  the  feed-screws,  the  out- 
lines of  the  templet  on  the  surface  of  the  work  are  accurately  fol- 
lowed. To  assist  in  doing  this  there  is  a  pointer  at  the  right  of 
the  work  which  remains  at  a  fixed  position  with  reference  to  the 
cutter  when  the  latter  is  below  the  surface  of  the  work,  and  indi- 
cates its  exact  position.  This  is  a  convenience  in  cases  where  a 
sharp  corner  is  to  be  made,  when  the  cutter  can  be  lowered  and 
the  cutting  continued,  guided  by  the  pointer,  thus  leaving  very 
little  to  be  filed. 

Although  die-milling  machines  are  not  built  usually  to  take 


358  TOOL-MAKING  AND 

very  large  work,  they  will  take  blanks  or  forgings  up  to  ten 
inches  wide  by  two  inches  thick  and  any  length. 

DIE-SINKING   ATTACHMENT. 

In  connection  with  machines  for  die-making,  a  die-sinking  at- 
tachment may  be  used,  and  if  a  great  number  of  dies  are  required 
to  be  sunk,  one  of  them  is  worth  having.  By  the  use  of  the  die- 
sinking  attachment,  the  skill  and  knowledge  necessary  to  the  suc- 
cessful use  of  small  chisels,  gravers,  riffles,  and  other  tools  of  the 
hand-die  sinker,  are  not  absolutely  .necessary,  and  a  good  die- 
maker  will  have  no  difficulty  in  doing  the  best  work  in  this 
line.  As  these  attachments  can  be  attached  to  die-milling  ma- 
chines in  a  few  minutes,  the  machine  is  converted  into  a  die- 
sinking  machine. 

MACHINE   FOE   FILING  DIES. 

In  a  number  of  shops  known  to  the  author  they  have  also  a 
special  machine  for  filing  the  dies  worked  out  in  the  die-milling 
machine.  This  machine  is  used  for  filing  to  a  finish  all  kinds  of 
blanking-,  trimming-,  punching-,  and  irregular  or  square-shaped 
drawing  dies,  or  anything  of  that  kind  that  has  to  be  filed  accu- 
rately. 

By  adjusting  the  table  of  this  machine  to  a  graduated  plate, 
any  desired  clearance  from  one  to  ten  degrees  can  be  obtained. 
By  setting  the  machine  at  zero,  the  walls  of  a  drawing-die,  a 
burnishing -die,  or  an  accurate  trimming-die  can  be  filed  or  lapped 
perfectly  square,  something  that  is  impossible  by  hand,  even  by 
the  most  skilful  die-maker.  In  these  filing  machines  care  must 
always  be  taken  to  have  the  upper  end  of  the  file  supported  by  ad- 
justing a  rest  provided  for  that  purpose.  The  amount  of  stroke 
in  machines  of  this  kind  can  be  readily  adjusted  by  a  slot-headed 
screw  in  the  driving- disc,  carrying  it  further  from  or  closer  to 
the  centre,  as  the  work  may  require.  For  fine  filing  a  short 
stroke  is  desirable. 

The  samples  of  die  work  shown  in  Fig.  428  are  only  a  few  of 
the  large  variety  of  dies  which  can  be  finished  in  half  the  time 
and  at  half  the  expense  usually  required  when  other  means  are 


INTERCHANGEABLE  MANUFACTURING.  359 

used.  Although  it  is  a  fact  that  skilful  workmen  cau  often  ac- 
complish the  most  astonishing  results  with  tools  which  are  far 
from  being  what  they  should  be,  an  equipment  of  up-to-date  tools 
is  always  to  be  desired  in  any  line  of  mechanical  work. 

A  DIE-SHAPEE. 

The  line  drawing  (Fig.  429)  shows  in  use  a  device  which  prac- 
tically converts  a  milling-machine  into  a  vertical  shaper,  or,  as 


Fig.  429. 

usually  miscalled,  a  slottiug-machine.  It  is  especially  service- 
able in  working  out  dies  for  punching-presses,  following  any  out- 
line, regular  or  irregular,  and  giving  the  required  clearance  all 
around.  As  will  be  seen,  the  attachment  may  be  used  upon  any 
milling-machine  of  the  standard  type,  and  when  once  fitted  may 
be  slipped  on  or  off  as  required. 


360  TOOL-MAKING   AND 

The  large  vertical  casting  seen  in  front  clamps  on  to  the  over- 
hanging arm  of  the  machine,  and  a  spindle  below  is  driven  by 
a  taper-shank  which  fits  the  machine  spindle.  Between  the  two 
bearings  which  are  provided  for  this  spindle  it  has  secured  to  it 
an  eccentric  or  cam  which  operates  a  horizontally  sliding  block 
which  works  in  the  cross-slot  of  a  vertical  slide  carrying  the  cut- 
ting-tool. The  vertical  stroke  obtained  is  \\  to  If  inches,  as  de- 
sired. The  cutting-tool  is  made  of  ^-inch  round  steel,  secured 
in  the  socket  by  a  set-screw.  This  tool  socket  is  separate  from 
the  vertical  slide,  and  when  the  tool  is  set  it  may  be  turned 
around  as  required,  so  that  any  outline  may  be  followed  and  all 
corners  may  be  worked  into.  A  clapper-block  has  been  pro- 
vided which  gives  perfect  clearance  for  the  tool  on  the  up-stroke. 

The  drawing  shows  the  tool  at  work  upon  a  half -die  of  irregu- 
lar outline.  This  die  is  mounted  upon  a  tilting-chuck  which  ac- 
companies the  attachment  and  provides  the  necessary  clearance- 
angle  for  die  work. 

It  will  be  noticed  that  the  middle  face  between  the  rings  is 
oblique  and  by  turning  these  the  pitch  is  thrown  in  the  different 
directions  required,  a  locking-pin,  a  clamping-screw  and  a  bar 
for  turning  the  rings  being  provided.  The  central  post  has  a 
spherical  head,  so  that  it  can  incline  as  the  angle  requires. 

A   SMALL   DIE-SLOTTEE. 

The  machine  shown  in  Fig.  430  is  suitable  for  all  such  work 
as  small  key-seating,  die-slotting,  both  straight  and  taper;  also 
internal  or  external  gear  patterns  where  draft  is  required,  and 
all  that  class  of  common  slotting  shown  in  Fig.  431. 

The  two  cross  motions  and  the  rotary  table  provide  for  fol- 
lowing any  outline. 

The  handle  for  the  rotary  table  is  arranged  for  using  dials  for 
dividing  purposes,  but  for  small  divisions  and  rapid  work  it  may 
be  entirely  removed,  and  the  table  revolved  by  hand,  using  the 
locating  device,  which  provides  twelve  divisions  for  square,  hex- 
agon, octagon,  etc. 

The  stroke  of  the  machine  has  been  fixed  at  24-  inches,  which 
is  ample  for  the  class  of  work  for  which  the  machine  is  intended, 
and  affords  greater  strengtli  than  an  adjustable  pin. 


INTEECHA NGEABLE  MANUFA CTTJRING. 


361 


The  speed  can  be  changed  by  means  of  the  cone  pulley. 

The  slide  for  the  ram  can  be  swiveled  five  degrees  either  way 
and  set  by  a  graduated  index,  thereby  insuring  the  same  draft 

to  every  part  of  the  die.  The  tool- 
block  is  well  adapted  for  holding  spe- 
cial tools.  It  swivels  in  a  centre  near- 
its  lower  end,  and  at  the  upper  end, 
carried  in  a  yoke,  are  two  hardened 
plugs  which  bear  on  a  cam  that  is 
bushed  into  the  lower  end  of  the  con- 
necting rod,  and  from  it  derives  a  par- 


FiG.  430. 


Fig.  431. 


tially  rotary  motion,  thus  locking  the  tool-block  on  the  down 
stroke  and  causing  the  tool  to  clear  on  the  up  strokes. 

A  DIE-FILING   MACHINE. 

The  die-filing  machine  illustrated  in  Figs.  433,  434,  and  435, 
while  being  designed  particularly  for  die-making,  is  now  in  use 
in  many  of  the  best-equipped  factories  in  this  country  at  a  variety 
of  other  work. 

A  great  deal  of  metal  pattern  work  may  be  done  on  this  ma- 
chine at  a  great  saving  of  expense.  Hardened  dies,  gauges,  etc. , 
may  be  lapped  much  faster  and  truer  than  by  hand.  A  variety 
of  small  parts  too  delicate  to  be  milled  may  be  filed  accurately 
aud  economically.  It  is  also  well  adapted  to  making  a  great 
many  templets  aud  forming-tools. 


362 


TOOL-MAKING  AND 


In  the  following  pages  I  illustrate  a  few  ways  in  which  the 
filing  machine  is  adapted  to  die -making  and  in  which  it  has 
proved  itself  a  success  by  actual  use  in  various  tool-rooms  where 
it  has  been  installed. 

In  filing  dies  by  hand  as  per  Fig.  432  a  man  must  work  in  a 
cramped  position  where  the  light  is  often  very  poor  and  where 


Fig.  432. 

the  lines  to  which  he  is  working  are  generally  on  the  side  away 
from  the  source  of  light.  He  must  watch  the  lines  and  keep  his 
surface  flat  and  true,  while  all  the  time  exerting  no  small  amount 
of  strength. 

Under  these  conditions  die-making  requires  a  very  high- 
priced  man  and  he  must  spend  a  good  part  of  the  time  in  testing 
the  accuracy  of  the  work  and  in  resting. 

With  the  filing  machine  the  work  is  flat  on  the  table  with  the 
lines  in  plain  view  and  where  it  will  obtain  the  best  possible  light. 

The  correct  amount  of  clearance  or  angle  is  accurately  ob- 
tained, and  the  file  moving  in  an  absolutely  straight  line  gives 
a  true,  flat  surface  with  no  rounded  edges.  Thus  the  operator, 
as  shown  in  Fig.  435,  is  relieved  of  these  details  and  may  devote 
his  attention  solely  to  guiding  the  work. 


INTERCHANGEABLE  MANUFA CTUEING. 


363 


The  machine  does  the  hard  work,  and  the  operator  is  in  a 
comfortable  position  and  able  to  do  more  and  better  work. 

The  cut  Fig.  433  shows  the  machine  sawing  out  a  die.  In  a 
variety  of  dies  the  lines  are  straight  or  nearly  so,  and  an  ordi- 


Fig.  433. 


nary  6-,  7-  or  8-inch  blade  may  be  used,  sawing  very  close  to  the 
lines,  giving  the  proper  shear  by  tilting  the  table,  and  leaving 
very  little  filing  to  be  done. 

For  smaller  work  a  narrow  blade  may  be  used  which  may  be 
turned  in  small  circles ;  there  can  be  had  a  4-inch  blade  ys¥-inch 
wide  with  wide  kerf  for  this  work. 

In  cut  Fig.  434  is  shown  the  manner  of  using  large  files  for 


Fig.  434. 


roughing.  The  file  is  clamped  rigidly  at  both  ends  and  the  work 
held  against  it  with  the  feed-screw  and  guided  by  hand. 

The  file  moving  straight  up  and  down  gives  no  chance  of 
rounded  edges  and  the  stock  may  be  removed  very  fast. 

Fig.  435  shows  the  method  of  finishing  small  work  with  small 
files.     The  file  is  held  in  the  lower  clamp  only,  the  upper  clamp 


364 


TOOL-MAKING. 


removed,  leaving  the  work  free  to  be  taken  out  and  examined 
at  will  without  disturbing  the  file.  The  file  clamps  are  made  to 
take  any  file  from  the  smallest  up  to  ^-inch  thick.  Saws  are  in- 
stantly adjusted  on  pins  on  the  file  clamps. 

File  clears  on  the  return  stroke  in  either  direction.  Clear- 
ance is  provided  for  the  file  whereby  it  is  held  clear  from  the 
work  on  the  return  stroke.     The  file  may  be  made  to  cut  on 


FIG.  435. 


either  the  up  or  down  stroke  by  changing  the  crank-pin  to  the 
opposite  end  of  the  crank-arm.  The  amount  of  clearance  is  ad- 
justable from  -^  to  0  by  means  of  a  knurled-headed  screw  at  the 
front  of  the  frame. 

Tilting  table.  Graduated  readings  are  provided  by  which  the 
machine  can  be  set  at  any  angle  with  mechanical  exactness. 
Files  a  straight  and  true  surface. 

Feeding.  A  screw  feed,  operated  by  hand,  is  provided,  by 
which  the  work  can  be  fed  to  the  file  in  any  direction  on  the 
table. 

An  adjustable  strap  is  provided  to  hold  the  work  down  to  the 
table.     This  is  especially  useful  in  sawing  and  heavy  filing. 

An  air-pump  is  provided  to  blow  away  the  chips  and  filings, 
by  which  the  work  and  file  are  kept  clean,  insuring  a  smooth  cut. 

Four  changes  of  speed  are  provided :  from  60  to  450  revo- 
lutions. 


CHAPTER  XXIV. 

The  Art  of  Working  Sheet  Metals  in  Dies  and 
Presses. 

USE  OF  SHEET  METAL  IN  PLACE  OF  OTHER 
MATERIALS. 

The  marked  progress  that  has  been  made  in  the  art  of  sheet- 
metal  working  and  that  made  in  the  use  of  the  power-press  for 
the  cheap  and  accurate  production  of  large  and  small,  plain  and 
ornamental  sheet-metal  parts,  during  the  last  decade,  has  led  to 
the  use  of  sheet  metal  as  a  material  in  the  construction  of  many 
articles  and  appliances  formerly  made  from  other  materials. 

Dies,  operated  by  presses — power,  foot,  hydraulic,  and  hand — 
do  a  stupendous  share  of  the  work  of  manufacturing  metal  goods, 
from  the  small  trouser  button  to  the  massive  boiler  head.  Not 
only  are  these  tools  vised  for  the  simpler  operations  required  in 
the  cutting  out  of  irregular  shapes  cheaply  and  accurately,  but 
for  bending,  twisting,  drawing,  embossing,  and  forging  opera- 
tions as  well. 

As  an  instance  of  what  is  being  accomplished  along  the  line 
of  sheet-metal  working  in  dies,  I  may  state  that  in  the  sample 
room  of  the  great  press  and  die  works  of  E.  W.  Bliss  Com- 
pany, of  Brooklyn,  N.  Y.,  may  be  seen  samples  ranging  all  the 
way  from  an  aluminum  mandolin  body  to  a  full-size  sheet-metal 
barrel,  and  from  sheet-metal  sinks  and  boiler  heads  to  aluminum 
automobile  bodies. 

Next  to  a  thorough  understanding  and  appreciation  of  the 
power-press  as  a  machine  tool,  a  practical  understanding  of  the 
most  approved  methods  -and  processes  for  the  economic  produc- 
tion of  sheet-metal  parts  and  articles  in  it  is  most  necessary  to 
those  engaged  in  the  working  of  sheet  metals.  Although  the 
number  of  establishments  where  sheet  metal  is  worked  in  dies  is 
great,,  there  are  many  where  the  most  approved  processes  are  not 

315 


366  TOOL-MAKING  AND 

known,  or  the  proper  construction  of  the  tools  is  not  understood. 
In  such  works  the  interdiction  to  the  rapid  and  accurate  produc- 
tion of  new  and  unusual  shaped  articles  lies  in  those  responsible 
for  results  not  being  familiar  with  the  construction  and  use  of 
suitable  tools. 

SIMPLEST   CLASS   OF   PRESS   TOOLS. 

The  simplest  class  of  tools  used  in  the  power  press  are  those 
for  ordinary  bending.  In  this  class  of  punches  and  dies  it  is 
necessary  to  combine  simplicity  with  durability  and  cheapness ; 
and  one  of  the  things  to  be  prized  is  an  ability  to  devise  simple 
and  effective  means  for  producing  in  the  fewest  number  of  opera- 
tions the  articles  required,  and  constructing  the  tools  so  as  to 
allow  of  being  set  up  and  operated  by  unskilled  help.  Very 
often  it  is  possible  to  design  a  die  that  will  accomplish  in  one 
operation  that  which  usually  requires  two  or  more  to -produce, 
being,  of  course,  of  a  more  complicated  and  accurate  construc- 
tion and  requiring  more  skill  and  intelligence  to  operate.  On 
the  contrary,  though,  it  is  often  preferable  to  increase  the  num- 
ber of  operations — by  adopting  simpler  methods — in  dies  that 
will  stand  rough  usage.  The  nature  of  the  work  and  the  quan- 
tity of  parts  required  should  determine  this. 

"GANG  "AND   "FOLLOW"   DIES. 

For  the  production  of  small  sheet-metal  articles  which  are  re- 
quired to  be  pierced,  bent,  formed  or  stamped  at  one  or  more 
points,  the  dies  should  be,  whenever  possible,  of  the  "gang"  or 
"  follow  "  types ;  that  is,  tools  in  which  gangs  of  punches  and 
dies  are  assembled  and  located  so  that  results  desired  in  the  fin- 
ished blank  will  be  accomplished  progressively  in  one  operation. 
It  is  only  by  the  use  of  such  dies  that  small  sheet- metal  articles 
can  be  produced  in  large  quantities  at  a  profit.  All  too  fre- 
quently dies  of  the  plain  or  "single "  type  are  used,  and  three  or 
more  sets  of  them  are  required,  when  the  same  results  could  be 
accomplished  in  one  operation  if  the  proper  attention  were  given 
to  the  devising  of  suitable  tools.  Wheu  sheet-metal  articles  are 
required  in  large  quantities  an  operation  saved  means  a  great 


INTERCHANGEABLE  MANVFAGTUBING.        367 

deal ;  and  if  two  operations  can  be  saved  even  at  the  outlay  of 
considerable  money  and  time,  the  results  attained  will  more  than 
compensate  for  all. 

PIERCING   OR   PERFORATING  DIES. 

The  construction  of  punches  and  dies  for  piercing  or  perforat- 
ing sheet  metal  is  comparatively  simple  and  no  very  intricate 
methods  are  involved.  Their  construction  is  usually  similar  to 
that  of  the  "gang"  type,  and  they  are  used  for  operations  on 
work  ranging  all  the  way  from  ornamental  thin  sheet-metal  arti 
cles  to  the  punching  of  holes  in  steel  beams  and  boiler  plates. 
The  holes  pierced  may  be  of  any  shape  and  spaced  as  desired. 
Often  a  number  of  small  blanks  are  produced  at  each  stroke  of 
the  press  by  dies  of  this  class ;  a  sheet  of  metal  of  the  required 
width  being  fed  to  the  dies  automatically.  Perforated  sheets  of 
different  metals  are  now  in  great  demand  and  are  used  for  a 
variety  of  purposes  too  numerous  to  mention. 

PROCESSES   FOR   DRAWN   WORK. 

For  the  production  of  drawn  and  formed  shells  from  sheet 
metal,  the  dies  in  general  use  consist  of  four  distinct  types.  The 
first  and  most  primitive  method  consists  of  punching  out  the 
blank  to  the  desired  shape  and  size  in  a  plain  blanking  die,  and 
the  pushing  it  through  the  drawing  die,  or  dies,  according  to  the 
desired  length  of  the  shell.  This  manner  of  producing  shells  is 
the  cheapest  only  where  a  small  quantity  is  desired.  The  second 
method  is  by  the  use  of  compound  dies  and  the  double-acting 
press,  in  which  the  blanking  punch  descends  and  punches  out 
the  blank,  and  then  remains  stationary  while  the  shell  is  being 
drawn  and  formed  by  the  internal  drawing  punch.  The  third 
method  is  by  means  of  a  punch  and  die  of  the  combination  type, 
in  which  the  punching  and  drawing  dies  are  combined  and  are 
used  in  a  single-acting  press.  This  method  is  by  far  the  most 
popular  and  generally  used  one,  as  well  as  the  most  practical  for 
the  pro(duction  of  plain  or  fancy  drawn  shells  which  are  not  re- 
quired to  exceed  one  inch  in  height.  The  design  and  method  of 
constructing  dies  of  the  combination  type  differ  according  to  con- 


368  TOOL-MAKING   AND 

ditions;  but  the  fundamental  principles  involved  are  substan- 
tially the  same  in  all  of  them,  and  may  be  adapted  for  the  pro- 
duction of  drawn  shells  of  any  shape  which  it  is  possible  to 
produce  in  one  operation  in  a  single-acting  press.  The  fourth 
and  last  method  of  drawing  shells  is  by  means  of  triple-acting 
drawing  dies;  they  are  used  to  produce  shells  which  are  required 
to  be  blanked,  drawn,  embossed,  lettered,  paneled,  in  one  opera- 
tion; and  are  used  in  triple-acting  presses. 

Farther  on  in  this  work  all  the  different  types  of  dies  used 
for  the  production  of  drawn  sheet-metal  work  are  fully  illustrated 
and  the  most  approved  methods  of  constructing  them  exhaust- 
ively described. 

DEPTH  WHICH   MAY  BE  DEAWN  IN   SHEET  METAL. 

The  depth  which  may  be  drawn  in  sheet  metal  in  one  opera- 
tion is  usually  equal  to  about  one -half  the  diameter  for  small 
cups,  and  one-third  for  large  vessels. 

Where  a  depth  greater  than  can  be  drawn  in  one  operation  is 
required,  it  is  necessary  to  accomplish  the  job  in  two  or  more 
operations ;  drawing  a  larger  and  shallower  shape  first,  and  after- 
ward reducing  the  shell  to  the  desired  size  and  shape. 

ANNEALING  AND   LUBKICATING  IN  DBA  WING. 

In  deep  drawn  work  the  edge  becomes  irregular,  and  requires 
trimming  before  finishing  the  piece.  It  is  also  necessary  in  such 
work,  or  in  other  cases  where  the  metal  is  severely  worked,  to 
anneal  the  metal  during  the  processes ;  but  tin-plate  is  ruined  by 
annealing ;  hence  such  work  is  drawn  and  annealed  before  plat- 
ing, or  if  some  stiffness  is  required  in  the  finished  articles,  one 
drawing  operation  may  be  performed  after  annealing  and  plating. 

When  drawing  bright  steel  it  is  necessary  to  use  oil  as  a  lubri- 
cant, and  apply  it  in  spots  over  the  sheets  before  they  are  worked 
up.  In  working  tin-plate  the  coating  of  tin,  together  with  the 
thin  film  of  oil  left  on  it  from  tinning,  are  ordinarily  sufficient 
lubricant;  but  in  drawing  large  pieces  in  a  double-acting  press  a 
stick  of  paraffin  wax  may  be  passed  once  around  the  edges  of  the 
blanks. 


INTERCHANGEABLE  MANUFACTURING.         369 

THE  DBA  WING   AND   FORMING   OF   DECORATED 
SHEET-METAL   ARTICLES. 

By  far  the  greatest  development  in  dies  for  the  drawing  of 
sheet  metal  has  been  along  the  line  of  decorated  tin  boxes.  The 
fundamental  practical  points  to  be  kept  in  mind  when  construct- 
ing dies  for  working  such  stock  are  as  follows:  Make  three  tem- 
plets— one  for  the  drawing  die,  another  for  the  drawing  punch, 
and  a  third  for  the  corners,  so  as  to  get  them  the  proper  radius. 
Finish  the  drawing  die,  the  punch  plate,  the  two  sides  of  the 
blank-holder  ring  and  the  inside  of  it,  and  the  drawing  die,  be- 
fore starting  on  the  cutting  die  or  punch.  Then  make  your  trial 
draws  until  the  proper  blank  is  found.  When  the  exact  blank 
has  been  found,  finish  the  cutting  die  and  the  outside  of  the 
blank-holder  ring,  and  fit  the  blanking  punch.  Take  a  cut  off 
the  die  base  after  the  die  has  been  hardened — this  base  should 
be,  of  course,  of  mild  steel.  For  decorated  metal  allow  about 
.006-inch  clearance  in  the  drawing  die;  that  is,  finish  the  draw- 
ing die  .006-inch  and  two  thicknesses  of  metal  larger  than  the 
drawing  punch;  while  for  plain  tin  allow  about.  0035-inch  clear- 
ance in  the  drawing  die.  By  giving  this  clearance  there  will  be 
no  necessity  for  easing  up  with  files  or  scraping  or  grinding,  and 
the  designs  on  the  metal  will  not  be  marred  or  scratched.  Round 
the  edges  of  the  drawing  die  smoothly ;  if  the  draw  is  very  short, 
-^  inch  will  be  enough,  and  if  long,  increase  it  accordingly.  Be 
careful  to  get  all  the  corners  of  the  drawing  punch  the  same 
radius  and  those  in  the  die  also  (plus  two  thicknesses  of  metal 
and  the  clearance)  and  lap  very  smooth.  By  keeping  the  fore- 
going points  in  mind  no  trouble  will  be  encountered  when  con- 
structing a  die  of  this  type  or  in  using  it  either. 

"FINDING"   THE    BLANKS    FROM   WHICH   TO    DRAW 

SHELLS. 

The  finding   of  the   proper  size  blank  for  drawn  shells  is 

usually  a  troublesome  matter ;  however,  the  way  to  figure  out  the 

approximate  size  of  a  blank  for  a  straight  cylindrical  shell  is  as 

follows :  Take  the  outside  diameter  of  the  shell  to  be  drawn  and 
24 


370  TOOL-MAKING. 

add  to  it  the  length  or  depth  of  same.  Then  add  to  this  ^  inch 
for  every  f  inch  of  depth,  and  the  resulting  total  will  be  very 
near  the  exact  size  of  the  required  blank.  For  deep  shells  this 
rule  will  allow  of  finding  a  blank  which,  when  the  shell  is  drawn, 
will  leave  enough  for  trimming ;  while  for  shallow  depths,  which 
will  draw  perfectly  straight  across  the  top,  a  slight  reduction  in 
size  will  be  necessary.  The  amount  to  deduct  will  become  ap- 
parent after  the  first  trial  draw. 

There  are  any  number  of  rules  for  figuring  the  side  of  blanks, 
in  which  the  principle  upon  which  the  finding  of  the  diameter  is 
based  is  that  the  area  of  a  drawn  shell  equals  the  area  of  the 
blank  from  which  it  is  drawn.  But  as  this  is  never  the  case,  be- 
cause of  the  fact  that  all  metals  stretch  and  run  unevenly  under 
drawing  pressure,  the  rules  work  well  only  on  paper.  The  way 
to  construct  a  drawing  die  in  the  shortest  possible  time  is  to 
figure  out  the  approximate  size  of  the  blank  in  the  manner  de- 
scribed in  the  foregoing ;  cut  out  and  file  up  a  templet  according 
to  the  result ;  make  the  drawing  portions  of  the  die ;  make  the 
trial  draws ;  discover  where  there  is  an  excess  or  a  deficiency  of 
metal ;  make  a  new  templet,  which  should  be  almost  perfect, 
draw  it  up,  and  if  found  correct  finish  the  cutting  portions  of  the 
die. 


CHAPTER  XXV. 

The  Making  and  Use  of  Punches  and  Dies  for  Sheet- 
Metal  "Working. 

Having  in  the  preceding  chapter  presented  the  fundamental 
principles  and  practical  points  which  are  necessary  for  the  tool- 
maker  to  know  in  order  to  construct  and  use  dies  successfully,  I 
will  devote  this  chapter  to  describing  and  illustrating  the  various 
types  of  dies  in  general  use.  The  designs  have  been  selected  as 
representing  the  most  advanced  practice  in  the  best  shops,  and 
may  be  adopted,  with  slight  modifications,  in  dies  for  the  pro- 
duction of  sheet-metal  parts  and  articles  in  endless  varieties. 

The  number  of  dies  shown  in  this  chapter  and  the  one  follow- 
ing is  sufficiently  large,  and  the  variety  representative  enough, 
to  allow  of  the  reader  comprehending  all  types.  When,  in  the 
case  of  the  descriptions,  it  has  been  found  expeditious  to  de- 
scribe means  and  ways  for  constructing,  this  has  been  done.  In 
fact  I  have  adopted  this  method  all  through  the  book ;  for  I  do 
not  think  it  is  enough  merely  to  illustrate  the  tool ;  the  mechanic 
is  also  interested  in  the  manner  in  which  it  should  be  made  and 
how  the  desired  results  may  be  accomplished. 

THE  MAKING  AND   USE   OF   SIMPLE  DIES. 

I  will  first  show  and  describe  a  number  of  dies  that  are  in- 
valuable for  use  in  the  average  machine-shop,  especially  the  job- 
bing tool-shop.  The  dies  shown  are  the  most  .simple  and  inex- 
pensive of  their  class  for  work  of  the  kind  shown.  Fig.  436  is 
known  best  among  die-makers  as  an  emergency  die — that  is,  a 
punch  and  die  for  producing  a  small  number  of  blanks  of  a  given 
shape  and  size,  of  which  the  blank  X  is  an  example. 

The  die  A  consists  of  a  piece  of  y'yinch  fiat  tool  steel,  planed 
and  fitted  to  the  bolster,  with  the  shape  of  the  blank  worked  out 
at  B  B.     In  dies  of  this  kind,  when  only  a  small  quantity  of 

371 


372 


TOOL-MAKING  AND 


blanks  are  to  be  punched,  the  clearance  or  taper  of  the  die  from 
the  cutting -edge  is  considerable,  as  the  more  clearance  given  the 
less  work  and  skill  required  to  finish,  allowing  the  blank  just  to 
fit  at  the  cutting-edge.  This  die  is  hardened  and  drawn.  For 
the  punch  a  cast-iron  holder  C  is  turned  and  finished  and  faced 
flat  and  smooth  on  the  front.  The  punch  D  consists  simply  of 
a  piece  of  ^-inch  flat  tool  steel  worked  out  and  sheared  through 
the  die  and  left  soft.  It  is  then  hard-soldered  to  the  face  of  the 
holder  C.  For  punching  blanks  from  thin  sheet  metal  to  the 
number  of  10,000,  this  die  is  all  right.     Although  some  may  say 


Fig.  436. 

"a  botch  job,"  the  results  will  be  found  to  be  all  that  is  required. 
This  style  of  die  is  used  universally  in  almost  all  of  the  fancy 
sheet-metal  goods  houses,  as  the  number  of  different  shapes,  and 
the  small  quantities  required,  necessitate  the  elimination  of  all 
unnecessary  expense. 

The  die  shown  in  Fig.  437  is  known  as  a  shearing  or  finish- 
ing die  for  heavy  blanks  and  is  used  for  finishing  work  such  as 
is  often  done  in  the  milling-machine,  or  grinder.  The  blank  Z, 
as  will  be  seen,  is  a  small  handle  punched  from  -g^-inch  mild 
steel.  In  punching  for  heavy  blanks  the  punch  is  always  fitted 
very  loosely  to  the  die,  and  the  blank  produced  is  generally  con- 
cave at  the  edges,  and  has  a  ragged  appearance  where  it  has  cut 


INTERCHANGEABLE  MANVFA  CT  URING. 


373 


away  from  the  rest  of  the  stock.  To  remove  these  defects  and 
marks,  the  blank  is  sheared  through  the  finishing  die,  Fig.  437, 
when  trimming  or  cutting  off  a  shaving  of  stock  all  around,  the 
blank  leaves  it  smooth  and  has  an  appearance  of  having  been 
milled.  In  making  dies  of  this  kind  one  of  the  blanks  that  have 
been  punched  is  taken  and  filed  and  finished  all  a*round  the  edges, 
removing  about  .003-inch  of  stock  all  around.  The  blank  is  then 
used  as  a  templet  for  finishing  the  die,  letting  it  through  from 
the  back  aod  filing  the  die  straight,  with  just  the  slightest  amount 


r^i 


Punch 


Blank- 


JL' 


9-, 


D 


Fig.  437. 

of  clearance,  being  sure  to  have  the  blank  a  good  fit  at  the  cut- 
ting-edge. The  inside  of  the  die  is  then  finished  and  polished  as 
smooth  as  possible  at  G  and  then  filed  taper  downward  from  H. 
I  is  the  gauge  plate  which  is  worked  out  and  finished  to  allow 
the  rough  blank  to  fit  nicely  within  it,  The  plate  is  fastened  to 
the  face  of  the  die  by  the  screw  J  and  the  dowels  K,  so  that  the 
blank  will  rest  on  the  face  of  the  die  I  with  an  equal  margin  all 
around  for  trimming.  Great  care  should  be  taken  in  adjusting 
this  gauge  plate  to  its  proper  position,  as  the  small  amount  of 
stock  to  be  trimmed  will  not  allow  much  leeway.     The  die  is 


374 


TOOL-MAKING  AND 


hardened  and  drawn  to  a  light  straw  color  and  the  face  is  ground 
and  oil -stoned,  leaving  it  as  sharp  as  possible.  The  punch  is 
constructed  in  the  regular  way  and  fastened  within  the  pad,  as 
shown.  The  punch  is  sheared  through  the  die  and  left  a  snug 
fit  within  it,  after  which  it  is  highly  polished  and  finished  and 
left  soft.  In  use,  the  blank  Z  is  placed  within  the  gauge  plate  I, 
and,  the  punch  descending,  it  is  sheared  into  the  die  at  G,  trim- 
ming and  finishing  it  all  around,  and,  if  the  die  has  been  pol- 


FlG.  439. 


Fig.  438. 


Fig.  440. 


ished,  leaving  a  nice  smooth  finish,  producing  as  good  a  job  as 
could  be  done  more  expensively  in  a  miller.  A  large  number  of 
different  small  pieces  in  demand  in  the  average  machine-shop, 
when  the  quantity  permits,  could  be  finished  at  a  greatly  reduced 
expense  by  this  means. 

When  a  nice  polish  or  finish  is  desired  on  the  work  the  blank 
is  forced  through  a  second  die,  which  is  relatively  the  same  as  the 
one  shown  in  Fig.  437,  except  that  it  tapers  slightly  from  the 
cutting-edge,  being  about  .002  inch  smaller  at  the  back  than  at 
the  cutting-edge.  This  die  is  also  highly  polished  and  finished, 
and  left  very  hard.  By  being  forced  through  the  die,  the  metal 
around  the  edge  is  slightly  compressed,  and  polished  by  the  fric- 
tion. I  have  seen  blanks  treated  in  this  manner  that  had  all  the 
appearance  of  having  been  polished  or  buffed.  This  die  is 
known  as  a  burnishing  die,  and  is  excellent  for  quick  and  cheap 
production. 

The  punch  and  die  shown  in  Fig.  438,  although  of  the  simplest 
design,  form  a  great  tool  for  accomplishing  by  inexpensive  means 


INTERCHANGEABLE  MANUFACTURING.  375 

results  that  generally  involve  considerable  time  and  cost.  The 
die  shown  is  for  finishing  square  holes  after  the  first  operation, 
and  T  the  appearance  after  being  finished.  Of  course  they  could 
be  finished  by  broaching,  but  the  punch  shown  is  the  better 
method.  After  the  holes  have  been  blanked  they  are  ragged  and 
uneven  at  the  edges.  They  are  also  left  undersize  about  .003 
inch. 

The  punch  8  is  first  finished  on  the  miller  to  a  perfect  square 
of  the  size  required — that  is,  .003  larger  than  the  blanked  hole. 
After  being  polished,  the  face  is  finished  dead  square  and  the 
edges  are  left  sharp.  The  punch  is  then  hardened  and  slightly 
drawn.  The  die  P  is  then  made  and  worked  out  until  the  point 
of  the  punch  can  be  entered,  and  then,  using  it  as  a  broach,  forc- 
ing it  into  and  through  the  die,  leaving  it  an  exact  duplicate  of 
its  shape.  The  die  is  then  filed  taper  from  the  back,  leaving  it 
straight  about  ^  inch  from  the  face,  as  shown  at  P.  After  the 
holes  for  the  dowel  and  stripper  screws  are  let  in,  the  die  is  pol- 
ished, hardened,  and  drawn  slightly.  The  edges  of  the  end  of 
the  punch  8  are  then  ground  and  rounded,  so  as  to  enter  the  hole 
in  the  stock  easily.  The  stripper  Q  consists  of  a  piece  of  ^ -inch 
flat  machine  steel  with  a  channel  milled  down  through  the  centre, 
in  depth  and  width  sufficient  to  allow  the  strip  of  steel  within 
which  the  holes  are  punched  to  pass  through  it  freely  without 
side  play.  A  small  pin  projecting  above  the  face  of  the  die  P 
at  the  left  side  acts  as  a  gauge  for  locating  the  holes  true  with 
the  die.  The  punch  and  the  die  being  set  up,  the  strip  is  in- 
serted within  the  gauge  or  stripper  plate  Q  with  the  first  hole 
under  the  punch.  The  punch,  descending  and  entering  the  hole, 
gradually  compresses  the  metal  and  finishes  it,  leaving  a  dead 
square  hole  with  a  nice  smooth  finish  on  all  sides.  The  punch 
shown  should  enter  the  work  for  a  full  inch  of  its  length.  This 
style  of  die  can  be  used  for  finishing  a  large  variety  of  differ- 
ent shaped  holes  in  heavy  iron  or  mild  steel,  where  they  are 
all  required  to  be  of  the  same  size  and  shape;  also  leaving 
a  finish  that  it  would  be  impractical  to  accomplish  by  other 
means. 


376 


TOOL-MAKING   AND 


PUNCHING   BRASS   CLOCK   GEARS— MOVABLE    STRIP- 
PING  DEVICES. 

The  gear  shown  in  Fig.  441  was  produced  complete  from 
^-inch-thick  sheet  brass.  Holes  were  required  to  be  punched  at 
A,  B  and  C,  five  sections  D  cut  away,  the  centre  hole  punched, 
and  the  teeth  cut.  The  gear  was  required  to  be  perfectly  true 
with  the  centre  hole  and  to  balance  evenly. 

A  cross-section  of  the  punch  and  die  is  shown  in  Fig.  442, 
with  a  plan  of  the  die  in  Fig.  443.  Three  successive  operations 
produce  the  gear.     The  three  holes  A,  B  and  C  and  the  large 


FIG.  441. 

centre  hole  are  pierced  in  the  dies  at  the  first  stroke,  the  sections 
D  are  punched  out  at  the  second,  and  at  the  third  stroke  a  fin- 
ished gear  is  cut  out.  Hardened  and  ground  bushings  are  used 
for  the  dies  h,  d  and  m  to  allow  of  easy  repairing. 

It  is  in  the  die  X  X  that  unusual  conditions  are  met.  This 
die,  used  for  punching  the  sections  D,  is  made  in  two  parts,  al- 
though this  might  not  appear  necessary  to  some.  The  work  to 
be  done,  however,  in  this  die  was  of  such  a  character  that  satis- 
factory results  would  have  been  impossible  with  a  solid  die. 

The  "  spider  "  used  in  this  die  is  shown  as  located  and  fastened 
in  position  in  Fig.  443,  and  in  detail  in  Fig.  444.  As  shown, 
there  are  five  arms  Z  and  a  hole  at  Y.     The  outside  of  the  wings 


INTERCHANGEABLE  MANUFA CTUBING. 


377 


are  turned  taper,  large  at  the  back  and  smaller  at  the  cutting 
face.  The  spider  was  left  large  all  over  and  hardened  and  drawn 
to  a  light  straw.     It  was  then  chncked  and  the  hole  Y  was  lapped 


to  the  size  of  the  hole  in  the  gear,  after  which  the  spider  was 
forced  on  a  mandrel  and  ground  all  over  to  size,  which  was,  to 


Fig.  443. 

say  the  least,  a  very  nice  job.  The  portion  X  X  in  the  die  plate 
was  bored  taper,  and  five  shallow  channels  K  were  cut  into  its 
walls,  as  locating  seats  for  the  wings  Z  of  the  spider. 

The  blanking  die  W,  in  which  the  gear  teeth  are  cut  and  the 
finished  piece  is  produced,  was  finished  by  reversing  the  usual 


378 


TOOL-MAKING   AND 


method ;  that  is,  instead  of  shearing  the  punch  through  the  die 
the  die  was  broached  by  the  punch.  As  will  be  seen  in  Fig.  442, 
this  punch  is  finished  with  a  stem  F  to  fit  a  hole  in  the  machine  - 
steel  holder  E  and  has  a  hole  straight  through  it  for  the  pilot 
pin  N.  The  teeth  in  the  punch  were  milled  and  finished  in  the 
same  manner  as  a  gear  would  be,  getting  as  smooth  a  finish  as 


Fig.  Ui. 


Fig.  415. 


possible.  The  punch  was  hardened  and  drawn  slightly,  after 
which  the  face  was  ground  and  stoned  keen.  The  die  W  was 
then  finished  by  using  the  punch  as  a  broach.  The  die  plate  V 
was  hardened  and  ground.  Then  the  punch  L  was  re-annealed 
and  sheared  into  and  through  the  die.  Thus  a  perfect  fit  was 
attained.     The  punch  was  left  soft. 

The  centre  piercing  punch  T  is  in  one  piece  and  is  let  into  a 
counterbored  seat  J  in  the  holder.  The  other  three  piercing 
punches  for  the  holes  A,  B  and  C,  Fig.  441,  are  of  drill  rod,  and 
are  located  in  strong  supplementary  holders,  as  shown  at  H,  8 
and  K. 

The  punch  (or  punches)  for  cutting  the  sections  D  in  Fig. 
441  is  shown  at  Q  Q  in  Fig.  442,  and  a  plan  or  face  view  of  it  in 
Fig.  445.  P  is  the  pilot  pin.  The  punches  Q  form  parts  of  the 
solid  piece  0  and  were  not  hardened ;  as  if  they  had  been  the 
resulting  distortion  woidd  have  made  a  fit  within  the  die  X  X 
and  the  spider  Z  impossible.  As  it  was,  by  shearing  the  sections 
Q  into  the  die  and  leaving  them  soft,  no  difficulty  was  expe- 
rienced getting  a  close  fit  at  all  points. 

The  only  part  requiring  further  description  is  the  stripper, 
which  is  of  unusual  construction.     As  shown  in  Fig.  442  it  is 


INTERCHANGEABLE  MANUFACTURING.         379 

located  on  the  punch,  or  "male"  die.  It  comprises  a  flat  mild- 
steel  plate  T,  fitting  around  the  punches  proper,  two  blocks  of 
hard-spring  rubber  U  U,  one  located  between  the  stripping- 
plate  and  the  punch-holder  face  at  each  end,  and  four  studs  of 
the  usual  construction,  not  shown.  One  of  these  studs  is  located 
at  each  of  the  four  corners,  with  the  heads  let  into  counterbored 
holes  in  the  back  of  the  holder  and  the  ends  screwed  into  the 
stripping-plate.  No  other  springs  were  required,  as  the  rubber 
blocks  answered  for  that  purpose. 

SPEING  STEIPPEES. 

Although  a  great  many  die-makers  claim  that  spring  strippers 
located  on  the  punch  should  not  be  used  where  a  stationary  strip- 
per can  be  located  on  a  die,  still  there  is  a  large  variety  of  work 
for  the  production  of  which  a  movable  stripper  must  be  used  if 
accurate  results  are  to  be  obtained. 

It  is  well  known  that  punching  or  perforating  dies  having 
stationary  strippers  will  distort  the  plates  or  articles  punched  by 
them,  and  often  to  such  an  extent  as  to  require  subsequent 
straightening.  Thus,  where  accurate  parts,  such  as  are  used  for 
clocks,  electric  instruments,  etc.,  are  produced  in  gang  dies,  the 
distortion  of  the  metal  as  it  is  worked  upon  by  the  various 
punches,  will,  when  stationary  strippers  are  used,  prevent  the 
production  of  satisfactory  work.  On  the  other  hand,  where 
movable  strippers  (any  of  the  various  types  I  mean,  and  not 
merely  the  one  shown  here)  are  used,  a  clear  space  is  left  be- 
tween the  punches  and  dies,  enabling  the  operator  to  manipulate 
and  observe  his  work  quickly  and  accurately.  The  stripper 
comes  down  on  the  strip  first,  straightening  and  clamping  it 
before  the  punches  enter,  while  the  pilot  jfins  locate  the  various 
operations  positively.  The  metal  is  held  under  pressure  while 
the  punching  and  stripping  are  being  done,  and  by  this  means 
the  work  comes  out  perfectly  straight  and  true.  Where  a  num- 
ber of  small  perforating  punches  are  required,  they  may  be  made, 
with  the  use  of  the  movable  stripper,  much  shorter  than  a  station- 
ary stripper  would  permit.  At  the  same  time  a  smaller  hole,  in 
proportion  to  the  thickness  of  the  stock,  may  be  pierced  because 


380 


TOOL-MAKING  AND 


of  the  close  support  which  the  movable  stripper  (when  well 
fitted)  gives  to  the  punches  up  to  the  point  where  they  enter 
the  stock. 

PUNCH    AND    DIE    FOE    END    FINISHING,      CUTTING 

OFF   AND   BENDING   SHEET  METAL  FEOM   THE 

STRIP   WITHOUT  WASTE. 

Up  at  the  left  in  Fig.  446  is  shown,  somewhat  enlarged,  the 
piece  made  by  the  punch  and  die  (Figs.  446  and  447).     These 


Oage  find 
Stripper 
Stock t    "    ■' ..■■■'■^■|i 


lax 


I  I  •     I 


W     •    (£ 


Stripper  aud        /Dte 


/        (gstopf 

— ^a       ) 


PIG.  446. 

articles  are  manufactured  by  the  million  and  are  used  as  protec- 
tive seals  for  wooden  boxes  and  cases,  their  use  preventing  the 
usual  loss  from  theft  while  cases  of  goods  are  in  transit.  They 
were  produced  in  one  operation,  without  waste,  from  •yL-inch- 
thick  cold-rolled  stock  of  the  required  width ;  and  the  efficiency 


INTERCHANGEABLE  MANUFA  CT UBING. 


381 


of  the  die  can  be  appreciated  from  the  fact  that  it  produced 
215,000  of  the  articles  shown  without  grinding. 

Fig.  446  is  a  plan  of  the  punch,  a  side  view  of  both  punch 
and  die,  and  a  plan  of  the  die  without  the  stripping  arrange- 
ments; while  Pig.  447  is  an  end  view  of  the  tools,  with  the 
stripper  and  the  inclined  fork  for  operating  it  in  position.     The 


. 

i 

i 

-3> 

1 

~\ 

O 

1 
1 

1 

Fig.  447. 

punch  consists  of  the  usual  cast-iron  holder  and  tool-steel  punch. 
The  punch  is  finished  at  one  end  to  act  as  the  cutting-off  and 
end-finishing  punch,  and  in  the  centre  as  the  bending  die,  the 
half -circular  groove  in  the  top  being  let  in  for  the  clearance  for 
the  stripper  pin  (see  Fig.  447).  The  punch  is  hardened  and 
drawn  to  a  dark  straw  temper. 

The  die  consists  of  a  flat  cast-iron  bolster  into  which  the  cut- 
ting-off and  end-finishing  die  and  the  bending  punch  are  located 
in  dovetailed  channels  and  fastened  by  flat-head  screws  let  in 
from  the  bottom  of  the  bolster.     The  adjustable  stop  plate  also 


382 


TOOL-MAKING   AND 


is  fastened  to  the  bolster.  The  stripper  arid  gauge  combined 
consists  of  a  piece  of  ^-inch  stock  with  a  channel  cut  down 
through  one  side  wide  enough  to  allow  the  stock  to  be  fed 
through  it  easily,  but  without  side  play.  It  is  fastened  to  the 
face  of  the  euttiug-off  die  by  four  round-head  screws,  as  shown 
in  the  plan.  As  shown  in  the  section  of  the  die,  the  beudiug 
punch  has  a  half-round  groove  let  into  the  face  to  correspond 
with  the  other  half  in  the  bending-die  portion  of  the  cutting-off 
punch.  The  cutting-off  die  and  the  bending  punch  are  hardened 
and  drawn  to  a  light  straw,  after  which  the  sides  of  the  bending 
punch  are  eased  off  a  bit  toward  the  bottom,  so  that  the  metal, 
when  bent,  will  cling  to  it  instead  of  to  the  bending  portion  of 
the  cutting-off  punch. 

The  stripping  arrangements,  as  shown  in  Fig.  447,  consists  of 
the  following  parts :  The  stripper  proper  is  a  round  stud  let  into 
a  small  casting  located  in  the  dovetailed  channel  for  the  bending 
punch  in  the  bolster.  This  stud  has  a  pin  let  through  the  back 
end  to  prevent  it  from  springing  out  too  far,  when  the  punch  is 
up,  by  the  action  of  the  spring  at  the  back.  A  stronger  pin  is 
let  through  the  enlarged  portion  or  collar  of  the  stud,  so  that  the 
inclined  fork,  which  is  fastened  to  the  back  of  the  punch -holder, 
will,  while  descending,  move  the  stripping-stud  back  and  off  the 
face  of  the  bending  punch. 

When  the  die  is  in  use,  a  strip  of  metal  is  entered  beneath  the 
gauge  plate  and  is  allowed  to  project  a  slight  distance  beyond  the 


Fig.  448. 


cutting  die.  The  press  is  stepped  and  the  end  of  the  stock  is 
trimmed  and  finished  to  the  shape  shown  in  the  plan  of  the  die. 
The  stock  is  then  moved  forward  against  the  stop,  and,  as  the 
punch  descends,  the  piece  is  cut  off  and  bent  over  the  bending 


INTERCHANGEABLE  MANUFACTURING.         383 

punch,  the  cutting  punch  descending  about  f  inch  below  the  cut- 
ting-edge of  the  die.  As  the  punch  ascends,  the  inclined  fork 
releases  the  stripping-stud  which  springs  outward  and  throws  the 
finished  piece  off  the  bending  punch  and  iuto  a  box  at  the  front 
of  the  press.  The  parts  are  thus  produced  without  waste  and  as 
rapidly  as  the  stock  can  be  fed.  At  first  strips  of  metal  were 
used  in  the  die,  but  after  a  short  time  rolls  of  the  required  width 
with  200  feet  of  stock  in  each  were  used.  They  were  placed  on 
a  reel  at  the  left  of  the  press  and  the  stock  was  fed  automatic- 
ally, through  a  pair  of  straightening  rolls. 

TWO   DIES   FOE   METAL   BOX-COENEE  FASTEXEES. 

The  article  shown  in  Fig.  448  is  a  sheet-metal  trunk  corner. 
These  corners  are  made  flat,  and  are  intended  to  be  bent  at  right 
angles  after  one  end  is  nailed  on  to  the  trunk.  The  notches  on 
the  sides  serve  as  guides  for  nailing  the  corner  in  the  proper 
position,  and  they  also  facilitate  the  bending.  The  corner  is  so 
made  that  the  edges  bind  the  wood  closely  when  nailed  on,  thus 
making  a  very  rigid  corner. 

Two  operations  are  necessary.  The  first,  that  of  notching  and 
cutting  off  the  blanks,  is  done  by  the  punch  and  die  shown  in 
Fig.  449,  showing  a  section  of  the  punch  and  die  and  a  plan  of 
the  die.  There  are  three  punches  fastened  in  a  machine-steel  pad, 
which  is  in  turn  fastened  to  the  face  of  the  holder  by  six  flat-head 
screws.  The  end-notching  and  cutting- off  punch  is  at  the  right, 
and  is  about  -£%  inch  shorter  than  the  centre  notching  punch  at 
the  left.  This  is  so  that  the  centre  notching  will  have  been  ac- 
complished before  the  blank  is  cut  off. 

The  die  is  made  in  the  regular  way,  with  two  short  gauge 
plates  at  the  right  end,  and  with  the  stripper  extending  entirely 
across  the  face  of  the  die.  When  the  blank  is  cut  off  it  drops 
off  at  the  back,  as  the  press  is  inclined  and  there  is  no  gauge 
plate  to  hinder  it. 

For  the  finishing  operation — that  of  drawing  and  forming  the 
six  raised  spots  and  perforating  them  in  the  centre — the  punch 
and  die,  Fig.  450,  are  used.  The  punch  is  in  a  dovetailed 
channel  in  the  holder  and  fastened  to  the  bolster  by  two  flat 


384 


TOOL-MAKING   AND 


screws  let  in  through  the  bottom.  The  dies  proper  are  six  tool- 
steel  bushings,  finished  on  the  face  with  a  forming  tool  to  the 
shape  required,  and  a  small  hole  let  down  through  the  centre. 
They  are  hardened  and  forced  into  counterbored  holes  in  the  die 
plate.     The  die  plate  is  beveled  at  the  edges  to  correspond  with 


,<T\. 


-fe- 


"-""■  .  ,      /"\ 


XotcblOg  Punch 


jtiil 


(~,A  Ap^^TTsf 


Fig,  449. 


the  punch  at  F  F.  The  die  plate  is  left  soft  and  the  punch  is 
hardened.  The  drawing-punch  sections  are  at  E  E  E  E,  and  are 
finished  as  shown  in  the  face  of  the  punch.  The  gauges  for 
locating  the  work  upon  the  die  are  three  in  number,  and  are 
located  ag  shown  at  G  G  G.  The  press  in  which  the  tools  are 
used  is  inclined  and  the  blank  is  placed  on  the  die  with  two 
sides  against  the  gauges  G  G  G.  After  the  punch  has  de- 
scended and  returned,  the  finished  work  remains  sticking  to 
the  die,   from  which  it  is  thrown  off  by  the  operator  by  his  en- 


INTERCHANGEABLE  MANUFA CTUBING. 


385 


tering  a  thin  fork  under  the  front  right-hand  end  and  snapping 
the  piece  off. 

Both  the  dies  shown  and  described  herein  were  used  in  a  sheet- 


-  _n a^M/""^-^-*. _2^a 


FIG.  450. 

metal  establishment  in  which  rapid  and  economic  production  is 
absolutely  necessary  in  order  for  their  products  to  sell  at  a  profit. 

PIEBCING   Am    SPBEADING  DIE   FOB   BOX    STBAPS. 

At  Fig.  451  is  the  outline  of  a  portion  of  sheet-metal  box 
strap  used  for  binding  the  edges  of  wooden  boxes.  These  straps 
are  produced  in  coils  of  from  5,000  to  6,000  feet,  with  slots 


FIG.  451. 


pierced  1\  inches  apart  along  the  entire  length.     These  slots  are 
first  punched  and  then  spread  to  make  openings  for  the  nails. 

The  spreading  of  the  slots  makes  the  opening  large  enough  for 

25 


386 


TOOL-MAKING   AND 


the  nails  and  does  away  with  the  liability  of  the  strap  breaking 
out  at  the  eyes  when  the  nails  are  driven  into  the  wood.  The 
material  is  T3¥  inch  wide  and  0.032  inch  thick. 

The  punch  and  die  used  to  produce  these  straps  are  shown  in 
Figs.  452,  453,  with  a  plan  view  of  the  punch  above  in  Fig.  452. 


FIG.  452. 


These  tools  show  how  very  frail  punches  may  bo  used.  The 
capacity  of  this  die  is  30,000  feet  of  stock  a  day,  fed  automatic- 
ally. 

The  punch  consists  of  the  stem  of  cast  iron ;  the  two  punch- 
holders  G  C  of  machine  steel ;  the  clamping  plates  G  G  of  the 
same ;  the  piercing  punch  B  and  the  spreading  punch  A ;  eight 
screws  for  fastening  the  clamping  plates  and  two  cap  screws  for 
fastening  the  holders  to  the  stem.  The  punch -holders  are  located 
in  square  milled  channels  F  F  in  the  face  of  the  stem,  and  are 
fastened  in  position  by  the  screws  D.  The  punches  are  of  uni- 
form section  and  double  ended,  and  are  located  in  seats  in  the 
holders  and  clamping  plates.  The  faces  are  sheared  so  that  two 
points  will  enter  the  stock  first  and  thus  the  holes  will  be  pierced 
progressively.  The  spreading  punch  A  is  bevelled  and  rounded 
at  the  face,  so  as  to  spread  the  stock  gradually.     These  punches 


INTERCHANGEABLE  MANUFACTURING. 


387 


are  hardened  in  oil  between  flat  plates  and  are  drawn  to  a  blue. 
They  last  a  very  long  time,  as  they  can  be  used  from  either  end 
and  ground  until  only  a  short  section  remains  in  the  holder.  By 
shearing  the  cutting  faces  of  the  piercing  punch  the  clamping  lid 
G  holds  it  tightly ;  it  is  surprising  how  easily  the  stock  is  pierced. 
The  construction  of  the  die  is  of  a  rather  novel  character,  and 
after  numerous  experiments  it  was  found  to  be  the  best.  It  con- 
sists of  the  usual  cast-iron  bolster,  with  two  dovetailed  channels 
let  into  the  face  for  the  dies,  the  dies  R  E  and  1 1,  screws  for 


Fig.  453. 


locating,  adjusting,  and  fastening  them,  the  stripper  and  gauges, 
which  are  combined  in  one  plate,  and  the  screws  and  dowels  for 
locating  and  fastening  it  to  the  face  of  the  bolster. 

The  piercing  dies  fit  tightly  in  the  dovetailed  channel  at  the 
right.  They  have  slots  as  clearance  for  the  fastening  screws  and 
to  allow  of  adjustment.  Pieces  of  T5¥-inch  flat  steel  at  each  end 
of  the  channel  serve  as  brackets  for  the  adjusting  set-screws 
K  K.  This  way  of  making  the  piercing  die  allows  of  the  faces 
being  ground  when  dull  with  very  little  trouble,  and  insures  its 
long  life.  The  spreading  die  is  in  one  piece  and  is  fastened  and 
located  within  the  channel  J  by  the  two  flat-head  screws.  In  the 
true  sense  of  the  word  it  is  not  a  die,  but  instead  a  support  for 
the  spreading  jranch  A.  The  stripper  and  gauges,  in  one  piece, 
are  machined  from  a  piece  of  f -inch-thick  machine  steel,  with  a 
narrow  channel  milled  down  along  one  side  as  a  gauge  for  the 
stock,  and  widened  at  the  left-hand  end  as  clearance  for  the  stock 


388 


TOOL-MAKING  AND 


after  the  pierced  hole  has  been  spread.  The  hole  in  the  stripper 
for  the  punches  is  a  tight  fit,  this  being  necessary  because  of  the 
frailness  of  the  punches;  the  stripper  is  heavy  for  the  same 
reason,  as,  in  order  to  accomplish  good  results  and  to  insure  the 
longevity  of  the  punches,  they  must  never  entirely  leave  the 
stripper. 

When  in  use  the  metal  is  fed  from  a  reel  at  the  right  and 
wound  up  again  on  a  reel  at  the  left,  the  press  running  contin- 
uously for  two  hours  without  any  attendance.  There  is  a  large 
variety  of  pierced  work  which  could  be  produced  at  the  minimum 
of  cost  by  dies  of  this  construction. 

AN   IMPROVED   PIERCING   DIE. 

Fig.  454  shows  an  improved  piercing  die,  used  in  the  same 
establishments  for  piercing  holes  in  100-foot  lengths  of  flat  cold- 
rolled  stock,  |  inch  wide  by  -^  inch  thick,  feeding  the  stock 


Fig.  454. 


automatically  as  described  for  the  first  die.     The  holes  pierced 
were  No.  24  gauge,  5-|  inches  apart. 

The  punch  pad  has  holes  bored  and  threaded  for  the  two 
punch-holders.  These  holders  are  turned  from  1^-inch  round 
stock,  with  holes  for  the  Stub-steel  punches.  They  are  flat  milled 
on  two  sides  for  a  wrench.  The  backs  of  the  punches  are  enlarged 
and  tapped  for  the  adjusting  or  butt  screws  M  M.  When  the 
punches  became  short  through  grinding,  a  piece   of  the  same 


INTERCHANGEABLE  MANUFACTURING. 


389 


stock  is  placed  between  them  and  the  faces  of  the  butt  screws. 
The  punches  are  fastened  by  the  set  screws  N  N  and  the  semi- 
circular faced  plugs  0  0,  thus  doing  away  with  the  notching  or 
flattening  of  one  side  of  the  punches  and  allowing  of  using  them 
for  a  greater  portion  of  their  length. 

The  die  is  composed  of  the  bolster,  the  two  piercing  dies, 
lapped  and  ground  to  size  and  forced  into  counterbored  holes  in 
the  face  of  the  bolster;  the  stripping  plate  and  gauges,  all  in 
one ;  the  two  punch  bushings  P  P  lapped  to  a  tight  fit  for  the 
punches,  and  the  screws  Q  Q  arid  dowels  R  R  for  fastening  and 
locating  the  stripper  plate  to  the  face  of  the  bolster,  as  shown. 

GANG  DIE   FOR   BOX-LID  FASTENING  PLATES. 

The  engraving  (Fig.  455)  shows  a  fastening  plate  used  for 
hasps  for  fruit  crates  and  box  lids,  and  Figs.  456,  457  show  the 


Fig.  455. 


punch  and  die  for  its  production.     The  article  has  three  holes 
pierced  in  it,  a  portion  of  the  centre  drawn  and  formed,  and  the 


PLAN  OF  PUNCH 


B  ~~c'   .''         B'     \ 


*  .  Fig.  456. 

ends  trimmed  to  a  curve.     The  stock  used  was  cold-rolled  sheet 
metal,  and  the  punch  and  die  were  of  the  "gang"  type. 

In  the  punch  A  is  the  stem  or  bolster,  I  the  punch  pad,  B  B 
the  two  small  piercing  jranches,  C  the  large  piercing  punch,  D 
the  drawing  and  forming  punch,  E  the  trimming  and  cutting-off 


390 


TOOL-MAKING   AND 


punch,  which  trims  and  cuts  off  at  F  and  G  respectively,  and  H 
the  six  flat-head  screws  for  fastening  the  punch  pad  to  the  holder. 

In  the  die  J  J  are  the  small  piercing  dies,  K  the  large  one,  L 
the  drawing  and  forming  die,  M  and  N  the  cutting  off  and  trim- 
ming die,  and  the  remaining  parts  the  stripper  and  gauge  plate. 
The  die  plate  was  hardened  and  drawn  to  a  light  straw.  The 
punches,  except  the  forming  and  drawing  punch,  were  hardened 
and  drawn  to  a  dark  blue,  the  drawing  punch  was  hardened  and 
drawn  from  the  back,  getting  the  back  soft  and  leaving  the  draw- 
ing face  very  hard. 

The  stock  is  fed  to  the  die  from  left  to  right  automatically, 
the  holes  being  pierced  first,  then  the  formed  and  raised  portion 


FIG.  457. 


drawn,  and,  lastly,  the  finished  plate  cut  off  and  the  front  end  of 
the  next  piece  trimmed.  The  drawing  punch  is  left  the  short- 
est; this  being  done  so  that  the  piercing  punches  will  have 
pierced  the  stock  and  the  finished  piece  have  been  cut  off  before 
the  raised  portion  of  the  next  piece  is  produced ;  thus  there  is  no 
shifting  of  the  metal  while  the  different  operations  are  being  ac- 
complished. The  metal  used  for  the  fasteners  came  in  rolls  of 
the  required  width.  It  is  straightened  somewhat  by  the  rollers 
of  the  automatic  feed  and  flattened  by  the  flat  portion  of  the 
drawing  punch. 


INTERCHANGEABLE  MANUFACTURING. 


391 


LAEGE   DRAWING  DIES  FOR   CIRCULAR  SHELLS. 

The  Figs.  458  and  459  show  a  collection  of  large  drawing  and 
re-drawing  dies  for  producing  from  flat  blanks  large  circular 
shells.  These  dies  were  made  in  the  works  of  the  E.  W.  Bliss 
Company,  and  formed  part  of  an  order  of  presses  and  dies  for  a 
sheet-metal-goods  concern  in  Europe.  They  were  made  to  metri- 
cal dimensions,  the  diameters  ranging  from  290  to  600  millime- 
tres or,  say,  from  11.4  to  23.6  inches,  the  largest  set  at  the  left 
and  the  smallest  at  the  right.  Each  set  consists  of  a  drawing 
punch,  a  drawing  die,  and  a  blank-holder.  Drawing  dies  of  this 
type  differ  from  those  used  for  small  work  in  that  they  draw  the 
articles  from  blanks  previously  cut,  instead  of  being  provided 
with  cutting-edges  which  punch  the  blank  at  the  same  stroke. 
The  outer  edges  of  the  drawing  dies  are  turned  to  the  same 
diameter  as  the  blank  to  be  drawn,  and  the  operator  locates  the 
blank  by  simply  laying  it  on  the  face  of  the  die  and  locating  the 
edges  with  his  fingers.  Very  often,  however,  shells  of  different 
heights  are  produced  in  the  one  die.  This  of  course  requires 
blanks  of  different  sizes  and  gauge  plates  to  locate  them  true  on 
the  die.     Dies  of  this  type  are  made  to  produce  large  shells  of 


Fig.  458. 


any  style  or  shape,  and  draw  the  article  at  one  or  more  opera- 
tions, according  to  the  shape  and  depth  to  be  obtained.  In  work 
of  considerable  taper,  such  as  large  flared  pans  of  thin  stock,  two 
or  more  blanks  may  be  drawn  at  the  same  stroke  of  the  press. 


392 


TOOL-MAKING  AND 


Fig.  458  shows  seven  sets  of  drawing  dies  with  inside  blank- 
holders.  As  shown  here,  they  are  used  for  re-drawing  shells 
which  have  been  first  drawn  in  dies  having  outside  blank-holders, 


Fig.  459. 


like  the  dies  shown  in  Fig.  459.     The  inside  blank-holder  holds 
the  partly  finished  articles  at  its  lower  bevelled  edges  between 


Cutting  PuiKh  and  Blank  Hold 


Fig.  460. 


the  bevelled  edge  of  the  punch  and  the  bevelled  seat  in  the  die, 

while  the  punch  draws  it  into  a  deeper  shape  of  reduced  diameter. 

These  drawing  and  re-drawing  dies  are  mostly  made  of  a  spe- 


INTERCHANGEABLE  MANUFA  CTUB1NG. 


393 


cial  grade  of  cast  iron,  treated  in  such  a  manner  as  to  give  a  very 
dense  and  uniform  texture  to  the  metal  at  the  working  surfaces. 
To  do  very  accurate  work,  however,  steel  rings  are  set  into  the 
dies,  and  the  blank-holders  are  made  of  steel  castings,  which  adds 
considerably  to  the  durability  of  the  tools.  For  shells  which 
have  to  be  finished  to  very  accurate  diameters  hard  steel  "siz- 
ing "  punches  and  dies  should  be  used  after  the  last  re -drawing 
operation. 


THE  DEAWIKG  OF  DEEP  SHELLS  FEOM  SHEET 

METAL. 

The  manufacture  of  deep  sheet-metal  shells,  of  small  diameter, 
has  progressed  constantly,  and  to-day  results  are  attained  which 
a  few  years  ago  were  only  thought  of  as  remote  possibilities. 

3-g-"mGH — 4-§-'dIAMETER 
■3^"  HIGH 4"d|AM. 

5^    HIGH  —  3-Jr  DIAM. 

: 6±   HIGH 3-f   DIAM. 

8"  HIGH 2|-'DIAM. 

10f-  HIGH 2|-  DIAM. 

13"  HIGH 2^~  DIAM. 

■16"  HIGH—  2"dI.AM. 


Fig.  461. 

The  operation  cf  drawing  sheet-metal  shells  has  really  changed 
but  little ;  the  same  means,  with  slight  modifications,  being  used 
at  the  present  time  for  the  production  of  deep  shells  of  small 
diameters  which  formerly  were  thought  practical  only  for  pro- 
ducing shells  of  shallow  depths  and  large  diameters.  The 
presses,  in  which  drawing  dies  are  used,  have  been  built  larger 


394 


TOOL-MAKING  AND 


and  stronger,  and  with  a  greatly  increased  length  of  stroke, 
while  the  dies  have  been  simply  modified  for  a  wider  range  of 
work. 

As  an  illustration  of  what  is  being  accomplished  in  the  draw- 
ing of  sheet  metal  we  show  in  Fig.  461  the  successive  results  of 
the  eight  operations  required  to  draw  a  shell  copper  -^  inch 
thick,  16  inches  deep  by  2  inches  in  diameter.  Two  of  the  shells 
are  assembled  and  shown  at  the  bottom.  They  are  used  as  parts 
of  a  patented  mineral -water  cooling  apparatus. 

The  blank  required  for  this  shell  was  8  inches  in  diameter, 
and  the  thickness  of  the  stock  decreased  from  -^  at  the  start  to 
The  die  used  for  the  cutting  and  first  drawing 


-^j  at  the  finish 


Fig.  462. 


operation  is  shown  in  Fig.  460,  and  is  of  the  double-acting  type. 
In  the  punch  the  cutting  and  blank-holder  part  is  a  forging  of 
wrought  iron  with  a  tool-steel  ring  welded  on  as  shown  for  the 
cutting  portion.  The  projection  B  is  for  locating  it  true  on  the 
outer  slide  of  the  press.     A  is  the  drawing  punch,  the  stem  of 


INTERCHANGEABLE  MANUFACTURING. 


395 


which  is  reduced  as  shown  to  fit  the  inner  slide  or  ram  of  the 
press. 

In  the  die,  I)  is  the  cutting-edge,  where  the  blank  is  cut ;  E 
the  face  upon  which  it  is  held  by  the  punch  while  being  drawn, 
jPthe  drawing  die,  and  G  the 
knock-out  pad.  This  die  is  set 
up  in  the  press  and  the  metal 
is  fed  to  it  and  blanked  and 
drawn  to  the  shape  shown  in 
the  first  operation  in  Fig.  465. 
The  press  has  a  toggle  move- 
ment which  insures  a  more  per- 
fect "dwell"  of  the  blank- 
holder  slide  than  could  be 
maintained  in  a  cam  drawing 
press,  and  effects  a  large  saving 
in  friction  and  power.  The  ad- 
justment of  the  drawing-punch 
plunger  is  effected  by  means  of 
a  double-ratchet  device,  which 
is  handy  and  quick  of  opera- 
tion. 

For  the  seven  re-drawiug 
operations  in  the  production  of 
the  shells,  dies  of  the  type 
shown  in  Fig.  462  were  used. 
These  dies  were  of  the  push- 
through  type  and  were  used 
without  the  usual  inside  blank- 
holders,  as  the  small  difference 
in  the  diameter  of  the  redrawn 
shells  did  not  require  it.  In- 
stead of  the  shell  being  pushed 
completely  through  these  dies, 
they  were  fed  to  the  top  of 
the  die  by  an  automatic  knock-out  on  the  press  in  which  they 
were  used. 

By  noting  the  difference  in  the  diameters  of  the  re-drawing- 


J 


Blank,  8  inches  diameter. 
FIG.  463. 


396 


TOOL-MAKING  AND 


operations,  Fig.  463,  the  manner  in  which  a  shell  of  small 
diameter  and  great  height  may  he  drawn  and  the  number  of 
operations  required  will  be  understood.  The  lubricant  used  in 
the  re-drawing  operation  was  lard  oil,  and  there  was  a  decided 
polish  on  all  the  shells  produced.  The  dies  used  for  the  re-draw- 
ing operations  were  made  from  a  special  grade  of  chilled  iron, 
while  the  punches  were  of  tool  steel.  Both  punch  and  die  for 
each  operation  were  highly  polished.  The  die  and  jmnch  used 
for  the  sizing  or  finishing  operation  were  of  tool  steel,  and  were 
hardened,  ground,  and  lapped  to  the  required  size.  As  will  be 
seen,  the  drawing  of  deep  tubes  of  small  diameters  is  not  such  a 
difficult  accomplishment  as  some  people  imagine ;  all  that  is  nec- 
essary being  the  adoption  of  proper  dies,  their  accurate  construc- 


I 


I  11  ft- 


Fig.  464. 


tion,  and  their  use  in  presses  which  have  been  built  specially  for 
such  work.  When  the  difference  in  the  diameters  of  the  re -draw- 
ing operations  exceeds  |-  inch,  inside  blank-holders  must  be  used. 
For  certain  metals  inside  blank-holders,  in  the  re -drawing  dies, 
will  allow  of  the  desired  results  being  accomplished  in  three  or 
four  operations  (through  the  perfect  holding  of  the  metal  while 
drawing  or  re-drawing),  which  would  require  six,  seven,  or  more 
operations  were  dies  adopted  in  which  inside  blank-holders  were 
not  used. 

Fig.  464  shows  the  tools  used.  The  punches  are  reduced  at 
the  end  and  threaded  to  screw  into  the  holder  in  the  press  ram. 
The  dies  are  shown  beneath  and  punches,  and  the  locating  seats 
in  each  are  shown  plainly.  The  devices  shown  at  the  bottom 
comprise  the  knock-outs  and  other  tools. 


INTERCHANGEABLE  MANUFACTURING. 


397 


HOLLOW   CUTTERS   FOR   PUNCHING   LEATHER, 
CLOTH,    AND   PAPER. 

When  work  is  to  be  punched  from  leather,  cloth,  or  paper, 
hollow  cutters  or  "clinking  dies,"  will  be  found  to  give  better 
satisfaction  than  the  punch  and  die  of  the  usual  construction,  as 

they  are  cheaper  to  make,  and  there 
is  practically  no  limit  to  the  number 
of  pieces  that  can  be  cut  at  one  stroke 
of  the  die,  which  may  be  operated  in 
the  ordinary  press,  or  by  hand  with 
the  use  of  the  mallet. 

The  die  is  made  from  stock  rolled 
specially  for  this  class  of  work,  and  is 
usually  composed  of  Swedish  iron, 
laid  up  with  a  good  grade  of  tool 
steel,  as  shown  in  cross-section  in  Fig.  465,  the  steel  being 
laid   on  the  straight  side   of  the  bar,   and  a  20 -degree  bevel 


Fig.  465. 


Fig.  466  a. 


FiG.  466  b. 


edge  given  to  what  is  to  be  the  outside  of  the  die.     A  templet 
is  made   of    sheet    metal    of    the  exact    shape    of    the   work 


FIG.  467. 


Fig.  468. 


wanted,  and  this  is  used  by  the  smith  in  welding  up  the  blanks. 
The  accuracy  with  which  forging  is  done  with  these  dies  is  re- 
markable, a  variation  of  y^  inch  from  the  pattern  being  the 
exception  rather  than  the  rule.  The  cutter,  after  being  welded, 
is  taken  to  the  vise  and  worked  out  on  the  inside  with  the  file  to 
the  exact  shape  of  the  templet ;  allowance  having  been  made  on 


398 


TOOL-MAKING. 


it  for  the  slight  amount  of  shrinkage  caused  by  the  hardening. 
The  die  is  then  finished  on  the  outside  by  grinding. 

When  the  tool  is  to  be  used  in  a  press  a  handle  will  not  be 
necessary ;  intended  to  be  used  by  hand,  a  handle  is  secured  to 
the  upper  part  of  the  die.  This  handle  is  forged  with  a  project- 
ing lip  shutting  over  on  the  outside  of  the  cutter,  the  weight  of 


FIG.  469.      " 

the  blow  being  taken  by  this  shoulder  which  bears  directly  on 
the  ivpper  part  of  the  cutter.  This  is  secured  in  place  by  rivets, 
and  is  then  taken  to  the  fire  and  brazed  in  the  usual  manner, 
using  borax  as  a  flux  and  soft  brass  solder  for  the  brazing.  This 
operation  is  generally  done  after  the  die  is  ground,  and  before  it 
is  tempered. 

Sometimes  the  die  is  used  in  an  inverted  position,  being  laid 

on  the  press  with  the  cutting-edge  up,  the  work  being  placed  on 

the  same,  and  as  the  gate  of  the  press  descends  the 

material  is  forced  through  the  die.    When  this  method 

is  practised,  the  die  should  be  brazed  to  a  foundation 

plate,  in  order  that  it  may  be  properly  secured  to 

the  press.     The  handle  or  this  foundation  plate  may 

be  removed,  and  the  die  may  be  repaired  or  worked  over  into 

other  shapes  if  required. 

For  a  surface  to  be  used  for  the  cutting-edge  of  the  die  to 
strike  upon,  there  is  nothing  better  than  a  built-up  block  of  hard, 
seasoned  rock  maple,  set  endwise  of  the  grain.  This  is  made  by 
sawing  up  a  plank  into  pieces  about  4  or  6  inches  long,  gluing 
them  up  into  a  block,  and  then  securing  it  by  bolt  passing 
through  the  whole,  as  shown  in  Fig.  469.  This  will  be  found  to 
give  better  results,  with  less  wear,  if  kept  damp ;  that  is,  a  wet 
cloth  should  be  laid  on  the  block  when  the  same  is  left  at  night. 
The  group  of  cutters  shown  in  Figs.  465-470  illustrate  several 
of  the  many  styles  of  "dinking  dies"  which  are  in  general  use. 


FIG.  470. 


CHAPTER  XXVI. 

The  Making  and  Use  of  Punches  and  Dies  for 
Sheet-Metal  Working. — Continued. 

A  PUNCHING   AND   CURLING  JOB. 

In  Fig.  471  are  shown  the  results  of  successive  operations  in 
the  production  of  a  sheet-metal  part  of  unusual  shape  which 
formed  part  of  a  patented  apparatus. 

The  upper  diagram  in  Fig.  471  shows  the  results  of  the  first 
and  second  operations.     The  holes  in  the  ends  were  punched,  the 


Fig.  471. 

ends  were  shaped,  cutting  off  the  piece,  and  twenty-nine  slots 
along  one  side  were  punched. 

The  piercing  of  the  holes,  shaping  the  ends,  and^cutting  off 
the  pieces  were  done  iu  the  first  operation  by  the  punch  and  die 
shown  in  Fig.  472.  The  work  in  this  operation  is  all  at  the  ends, 
necessitating  a  punch  and  die  of  different  construction  from  those 
usually  used.  In  the  die  section  the  die  for  piercing  and  that 
for  cutting  off  and  end-shaping  are  dovetailed  into  the  face  of 
the  cast-iron  bolster,  one  at  each  end,  and  secured  by  taper  dowel  - 
pins.  The  gauge-plate  extends  along  the  entire  length  of  the 
bolster,  and  is  fastened  to  the  die  faces  with  the  stripper  plates 
by  fiat-head  screws.  The  stripper  plates  are  made  of  extra  heavy 
stock  and  are  worked  out  so  that  the  punches  are  supported  while 
doing  their  work.  In  the  punch  section  the  construction  is 
similar  to  that  followed  in  the  die  section,  in  that  the  cutting- 


400 


TOOL-MAKING   AND 


off  and  end-finishing  punch  is  dovetailed  into  the  holder  and 
located  by  means  of  a  taper  dowel ;  while  the  piercing  punches 
are  let  into  a  pad,  dovetailed  into  the  holder,  and  located  in  the 
same  manner  as  the  cutting-off  punch.     The  piercing  punches 


Fig.  472. 

were  made  of  drill  rod,  hardened,  tempered,  and  of  a  length 
sufficient  to  allow  of  their  always  being  in  the  stripper,  thus  ob- 
viating the  tendency  to  bend  or  snap  off.  The  stock,  which  re- 
quired no  side  trimming,  was  fed  across  the  die  faces  automatic- 
ally.    The  four  holes  were  pierced  at  the  left,  and  then  the  last 


Fig.  473. 

end  of  the  piece  and  the  first  end  of  the  next  piece  shaped,  and 
the  piece  was  cut  off  by  the  large  punch  at  the  right. 

For  the  second  operation,  that  of  piercing  the  twenty-nine 
slots,  a  punch  and  die  of  intricate  and  accurate  construction 
were  required.     In  Fig.  473  are  shown  a  front  elevation  partly 


INTERCHANGEABLE  MANUFACTURING .         401 

in  section,  and  a  vertical  cross  section,  respectively.  I  illustrate 
only  the  punch,  as  the  die  was  almost  identical  in  construction. 
The  punch  section  consists  of,  first,  a  cast-iron  holder  C,  then  a 
supplementary  puDch-holder  A,  the  latter  in  two  sections,  the 
twenty-nine  punches  D,  and  a  spring- actuated  stripper  H.  The 
spring  stripper  is  left  off  the  plan  so  that  the  construction  of 
the  other  parts  may  be  more  clearly  understood.  The  manner 
in  which  the  punches  are  located  and  fastened  is  unusual.  First 
two  pieces  A  of  ^--inch -thick  annealed  tool  steel  were  planed  to 
butt  together  sidewise  and  then  dovetailed  into  C.  These  two 
sections  were  then  clamped  together,  and  twenty-nine  slots  were 
milled  into  them,  in  depth  equal  to  half  the  width  of  the  pierc- 
ing punches.  The  manner  in  which  the  punches  were  let  into 
these  slots  and  upset  at  the  back,  the  two  sections  strengthened 
by  dowels  B  B,  and  then  driven  into  the  dovetailed  channel  in 
the  holder,  will  be  understood,  as  well  as  that  the  milling  of  the 
slots  in  the  sections  A  A  of  the  pad  was  an  accurate  job.  It  was 
accomplished  by  careful  work  on  the  universal  milller.  The 
slots  were  milled  about  .002  inch  smaller  than  the  thickness  of 
the  punches.  The  making  of  the  twenty-nine  punches  was  also 
a  job  requiring  skill  and  care.  The  punches  were  left  over  size 
all  over,  then  hardened  between  oiled  plates  and  drawn  to  a  dark 
straw  to  within  ^--inch  of  the  backs,  and  from  there  on  to  a 
dark  blue  to  allow  of  upsetting  them  within  the  pads  at  the 
backs.     They  were  then  ground  on  all  sides  to  size. 

The  spring  stripper  plate  H  H  was  worked  out  to  fit  around 
the  punches  rather  snugly,  so  as  to  give  them  as  much  support 
as  possible  up  to  the  point  where  they  entered  the  stock.  The 
faces  of  the  punches  were  sheared  so  as  to  commence  to  cut  at 
both  edges  before  the  centre  of  the  stock  was  cut  away.  This  is 
shown  in  the  end  view  at  I. 

The  die  was  made  in  the  same  way  as  the  pad  A  A,  being  in 
two  sections,  which  were  located  together  by  dowels,  and  were 
dovetailed  into  a  bolster  of  the  usual  kind.  Considerable  care 
was  required  in  the  hardening  of  the  die  section,  and  in  the  grind- 
ing of  the  faces  afterwards,  in  order  to  insure  the  alignment  be- 
tween the  twenty-nine  piercing  dies  and  the  punches ;  and  al- 
though the  man  who  hardened  them  understood  his  business  and 
26 


402 


TOOL-MAKING   AND 


turned  out  a  good  job,  it  was  necessary  to  peen  the  edges  of  some 
of  the  pad  slots  so  as  to  crowd  a  few  of  the  punches  over  a  thou- 
sandth of  an  inch  or  so.  It  was  not  found  necessary  to  grind  all 
of  the  dies,  although  about  every  third  one  had  to  be  touched  up 
on  the  sides  with  a  fine  wheel,  taking  care  just  to  touch  the  tight 
spots. 

When  using  the  punch  and  die  a  blank  was  located  against 
stops  on  the  face  of  the  die  and  the  press  was  "stepped."     As 

the  punch  descended  the  spring 
stripper  plate  H  H  flattened  the 
stock  aud  held  it  securely  in  posi- 
tion while  the  slots  were  being- 
punched.  As  the  punch  rose,  the 
stripper  forced  the  work  from  the 
punches  and  allowed  it  to  drop  off 
the  die  face.  After  the  punch 
and  die  had  been  in  use  a  short 
time  it  was  found  necessary  to 
re -grind  the  die  faces,  as  some 
of  them  had  .sheared.  Then  the 
punches  were  entered  into  the  dies 
and  solder  was  run  around  them 
at  the  pad  faces.  This  rendered 
the  alignment  perfect,  and  we 
had  no  more  trouble. 

It  will  be  seen  in  Fig.  471 
that  the  sections  left  between  the 
1  slots  punched  in  the  second  ope- 
ration have  to  be  curled  alter- 
nately, half  of  them  one  way  and 
the  other  half  the  other  way. 
It  was  at  first  thought  that  a  die 
of  considerable  intricacy  would  be  necessary ;  but  it  was  at  last 
decided  to  do  the  curling  in  two  operations — but  with  one  die, 
and  that  a  quite  simple  one. 

I  show  in  Fig.  474  a  vertical  cross-section  of  the  curling  die. 
L  is  the  punch-holder;  K the  curling  punch,  located  in  a  square 
channel  in  the  holder  face  and  fastened  by  three  flat-head  screws; 


Fig.  474. 


INTERCHANGEABLE  MANUFACTURING. 


403 


N  N  are  the  portions  that  do  the  curling,  while  the  cutaway  sec- 
tioDS  E  are  clearance  channels  for  the  sections  of  the  stock  which 
have  to  be  curled  in  the  opposite  direction.  P  is  the  work,  Q  a 
spring  supporting  pad  with  the  face  worked  out  at  0  to  the 
radius  of  the  curl;  U  is  a  gauge-plate  for  locating  the  work 
against  the  pad  Q ;  R  is  the  bolster ;  8  the  channel  in  which  the 
spring  supporting  pad  nroves,  and  T  one  of  three  spring  studs. 
The  work  is  placed  between  the  gauge  U  and  the  pad  Q  and 
against  a  gauge  at  the  end.  As  the  punch  descends,  half  of  the 
sections  to  be  curled,  or  every  other  one,  enter  the  curling 
grooves  N,  while  the  others  enter  the  clearance  channels  W. 
The  punch  continues  to  descend  and  the  metal  follows  around 
the  curling  grooves  until  the  curls  are  completed,  the  pad  Q 
descending  with  the  punch.  As  the  punch  rises,  the  pad  Q  rises 
also  and  carries  the  work  out  of  the  locating  slot  between  the 
pad  and  the  gauge,  and  as  the  punch  rises  higher  it  leaves  the 
work  free  on  the  top  of  the  pad  Q  from  which  it  is  removed  by 
hand.  The  fourth  operation,  curling  the  remaining  sections  in 
the  opposite  direction,  is  accomplished  in  precisely  the  same 
manner. 

DIES   FOE   SHEET-METAL   BAG-CLASPS. 

In  Fig.  475  are  shown  three  views  of  a  patented  sheet- metal 
bag- clasp  which  was  produced  entirely  by  the  use  of  dies,  there 


Fig.  475. 


being  no  hand  work,  except  in  feeding.     The  dies  here  shown 
are  the  most  interesting  ones  of  the  set  employed. 

The  clasp  consists  of  eight  parts:  the  embossed  front  A,  a 


404 


TOOL-MAKING  AND 


thin  tin  pad  B  fitting  into  the  embossed  part  at  the  back,  the 
hook  or  clasp  part  O,  the  spring  D,  the  lever  E,  the  two  straps  F 
in  which  it  is  located,  and  two  rivets  G  for  fastening  the  spring 
I)  to  the  hook  (7. 

The  first  part  produced  was  the  embossed  front  A.     This  was 
struck  up  and  drawn  from  very  thin,  soft  sheet-brass  blanks, 


Fig.  476.  Fig.  417. 

which  had  been  previously  cut,  the  result  being  shown  in  Fig.  476. 
The  second  operation  on  the  embossed  piece  was  punching  out  the 
drawn  and  embossed  portion  from  the  rest  of  the  blank,  leaving 
the  scrap  as  at  Fig.  477.  The  piece  produced  has  four  small 
wings,  which  are  afterward  bent  upward  in  a  simple  die  in  the 


rH  IT 

The  Work 

!"j      h 

1 

I 

EIG.  478. 

foot-press  and  then  bent  inward,  enclosing  the  pad  within  the 
embossed  part.  The  die  for  the  trimming  and  blanking  opera- 
tion is  shown  in  Fig.  478.  The  punch  has  a  spring  stripper, 
while  the  face  of  the  die  is  open  and  clear;  thus  the  locating  of 
the  work  is  rapid,  the  work  being  pushed  through  the  die  and 
the  spring  stripper  stripping  the  scrap  from  the  punch  when  it 
slides  off,  the  press  being  tilted. 


INTERCHANGEABLE  MANUFACTURING.         405 


In  Fig.  479  we  have  the  punch  and  die  used  to  produce  the 
pad  shown  at  the  top  of  the  cut.  The  work  consists  of  cutting 
and  bending  up  the  four  wings  G  and  punching  out  the  blank  to 
the  shape  shown.  The  tools  used  for  producing  this  part  were 
of  the  combination  blanking,  piercing,  and  bending  type,  com- 
pleting the  work  at  one  stroke  of  the  press.  In  the  die  N  is  the 
bolster,  0  the  blanking  die,  Q  the  piercing  and  bending  punch 


FIG.  479. 

pad,  R  R  two  of  the  piercing  and  bending  punches,  P  the  spring 
stripper  in  the  die,  8  the  spring,  T  T  the  two  gauge  plates  be- 
tween which  the  stock  is  fed,  and  U  the  stripper  for  the  stock. 
In  the  punch  if  is  the  holder,  J"  the  blanking- punch,  K  K  two  of 
the  piercing  and  bending  dies,  I  the  punch  pad,  and  L  the  punch 


406 


TOOL-MAKING  AND 


stripper.  The  press  was  tilted  backward,  the  stock  was  fed  from 
front  to  back,  and  the  finished  piece,  after  being  stripped  from 
the  punch,  dropped  off  into  a  box. 

In  Fig.  480  we  have  the  clamp  portion  before  the  bending 
operation.     In  the  production  of  this  part  four  operations  were 


Fig.  480. 


necessary.     The  first  was  the  punching  out  of  the  plain  blank. 
This  was  done  in  a  simple  blanking  die.     The  second  and  third 


EE 


operations  were  both  done  in  one  combination  die.     The  tools 
are  shown  in  Figs.  481,  482,  and  483.     The  work  to  be  done  by 


INTERCHANGEABLE  MANUFA CTUEING. 


407 


these  tools  is  the  piercing  of  the  eight  slots  X,  Fig.  480,  the  pierc  - 
ing  of  the  two  holes  W,  the  drawing  of  four  shallow  seats  for 
locating  the  straps  shown  at  F  in  Fig.  475,  the  throwing  up  of 
three  small  projections  Y,  and,  lastly,  the  bending  of  part  F~to 
the  shape  shown  by  the  dotted  lines  in  the  edge  view,  Fig.  480. 

In  the  dies,  Fig.  481,  E  E  is  the  section  where  all  the  pierc- 
ing is  done,  and  F  F  the  section  where  the  forming,  drawing,  and 


Holler 


Plan  of  Punch. 

Fig.  482. 


bending  are  done.  As  shown,  the  two  sections  are  locked 
together  at  2  2.  The  bolster  used  with  the  dies  is  not  shown. 
However,  the  dies  were  located  in  a  channel  and  held  and  fast- 
ened in  position  by  set-screws  at  each  end  of  the  channel.  In 
die  E  E,  where  the  piercing  is  done,  5,  3  and  4  are  the  piercing 
dies,  6  6  the  two  gauges  which  locate  the  blank  for  piercing,  and 
7  the  stripper.  The  gauge-plates  and  stripper  are  located  and 
fastened  by  the  dowel-pins  9  and  the  two  flat-head  screws  8.  In 
the  section  F  F,  where  the  drawing,  forming,  and  bending  are 
done,  10  10  are  the  seat  drawing  dies,  11  is  where  the  small  pro- 
jections are  formed,  and  12  where  the  neck  Fof  the  work  is 
bent ;  13  13  are  the  two  gauge-plates  between  which  the  work  is 
located,  while  14  are  the  stripping  edges. 

The  punch-holder,  Figs.  482  and  483,  is  of  the  usual  construc- 
tion, while  the  method  of  locating  and  fastening  the  punches  is 
somewhat  different  from  that  usually  followed.     The  drawing, 


408 


TOOL-MAKING  AND 


forming,  and  bending  punches  are  all  contained  in  one  steel 
block,  which  is  worked  out  on  the  face  to  match  the  dies  in  F  F. 
This  block  is  dovetailed  into  the  holder,  and  is  then  fastened 
and  located  in  alignment  with  the  dies  by  the  set-screws  shown 
at  the  side. 

The  section  of  the  punch-holder  devoted  to  the  piercing  opera- 
tion is  built  in  the  usual  manner ;  that  is,  a  machine-steel  pad, 


in  which  all  of  the  piercing  punches  are  located,  is  fastened  to  the 
face  of  the  holder  at  this  side  by  four  flat-head  screws. 

The  piercing  punches  were  rather  slender  and  frail,  and  it 
was  necessary  to  be  very  careful  in  locating  them  in  the  pad. 
This  was  accurately  accomplished  by  working  out  the  pad  and 
the  piercing  dies  at  the  same  time.  Then  the  punches  were  fin- 
ished to  fit  the  dies,  hardened  and  drawn,  and  then  forced  into 
the  pad,  upset  at  the  back,  and  hard  solder  run  around  them  at 
the  face  of  the  pad.  As  the  holes  for  them  in  the  stripper  were 
made  good  fits,  and  as  the  stripper  was  of  considerable  thick- 
ness, all  danger  of  bending,  twisting,  or  breaking  was  obviated, 
as  the  punches  never  left  the  stripper. 

The  dies  E  E  and  F  F  were  hardened  and  drawn  a  very  little. 
The  punch  block,  in  which  the  drawing,  forming,  and  bending 
dies  were  contained,  was  hardened  on  the  face  and  left  hard. 
All  of  the  slot-piercing  punches  were  hardened  between  oiled 
plates,  while  the  two-hole  piercing  punches  were  hardened  in  oil. 

Eeferring  to  Fig.  475  we  have  the  flat  spring  part  D  of  the 
clasp  to  complete  the  article.  It  is  necessary  to  round  off  one 
end  of  this,  punch  teeth  in  the  other  end,  punch  two  small  holes, 
throw  up  a  small  lug,  and  bend  and  form  the  metal  to  a  given 


INTERCHANGEABLE  MANUFACTURING. 


409 


shape.  All  of  the  work  on  this  spring  was  done  in  the  fol- 
low-die  shown  in  Fig.  484.  The  stock,  coming  to  the  proper 
width,  was  fed  between  the  gauge-plates  on  the  die  and  against 
the  stop-pin  by  an  automatic  roll  feed,  and  then,  the  punch  de- 
scending, the  holes  were  pierced  and  the  front  end  was  trimmed. 


FIG.  484. 

At  the  next  stroke  the  teeth  were  punched  in,  the  piece  was  cut 
off,  bent,  and  formed,  and  projection  was  thrown  up,  the  front 
end  of  the  next  piece  was  trimmed  and  the  two  holes  were 
pierced.  This  die  was  an  exceptionally  rapid  producer,  an  in- 
clined press  being  used  and  the  finished  parts  falling  off  at  the 
back. 

For  producing  the  straps  in  which  the  lever  worked  a  die 
which  produced  three  at  once  was  used  for  blanking,  while  the 
bending  was  done  in  a  simple  little  push-through  die  in  the  foot- 
press.  The  lever  was  cast.  In  assembling  the  various  parts  to 
form  the  complete  article  shown  in  Fig.  475  a  few  foot-press  dies 
of  very  simple  construction  were  used. 


410 


TOOL^MAKING   AND 


A   TBIPLE-ACTION    DIE    FOE   BLACKING,   DBA  WING, 

AND   EMBOSSING   AN   ALUMINUM   SHELL  AT 

ONE   OPEBATION. 


As  as  instance  of  what  is  being  accomplished  at  one  opera- 
tion in  the  line  of  embossed  shells,  I  show  in  Fig.  485  two  views 
of  a  shell  which  formed  the  cover  of  a  box  for  a  toilet  prepara- 
tion, and  for  which  an  order  for 
almost  one  million  was  secured. 
The  material  used  was  sheet  alu- 
minum of  a  special  alloy,  and  the 
result  in  the  finished  shell  was  very 
pretty. 

A  triple -action  "Bliss  "  cutting, 
drawing,  and  embossing  press  and 
a  triple- action  die  were  used.  The 
chief  advantage  to  be  gained  by 
the  use  of  triple-action  dies  lies  in 
the  fact  that  the  finished  work  from 
them  is  delivered  below  the  die  in- 
stead of  at  the  top,  thus  enabling 
the  operator  to  feed  the  metal  con- 
tinuously, instead  of  waiting  for  each  piece  to  come  to  the  top  of 
the  die  and  be  removed  or  slid  off  before  the  next  can  be  cut. 

Fig.  486  is  a  vertical  section  of  the  lower  or  die  portion, 
showing  the  die  parts  in  j>osition  on  the  press  bolster  and  the 
lower  plunger.  Fig.  487  is  the  upper  or  punch  portion.  In  Fig. 
486  A  is  the  press  bolster,  B  the  raised  or  bridge  bolster  on  which 
the  cutting  and  drawing  die  J  is  fastened,  and  D  the  lower 
plunger  with  the  embossing  die  M. 

The  cutting  and  drawing  die  J  is  in  one  piece.  It  was  a  forg- 
ing of  mild-steel  base  and  a  tool-steel  face  for  the  cutting  and 
drawing  portions.  F  is  the  cutting-edge,  sheared  as  shown  at 
G ;  H  the  surface  on  which  the  blank  is  held  while  being  drawn ; 
J  the  drawing-die  portion,  and  X  the  stripping  edge.  The  die 
is  fastened  to  the  face  of  the  bridge  bolster  by  the  cap-screw  K. 
L  is  a  clearance  hole  in  the  bridge  bolster.     The  embossing  die  is 


Fig.  485. 


INTERCHANGEABLE  MANUFA  GTUBING. 


411 


secured  to  the  face  of  the  lower  plunger  by  the  two  screws  0. 
N  shows  the  embossing  face  of  the  die. 

Iu  the  upper  part  of  the  punch  part,  Fig.  487,  Q  is  the  com- 


Fig.  486. 

bined  drawing  and  embossing  punch,  and  P  the  cutting  punch 
and  blank-holder,  which  locates  on  the  face  of  the  outer  ram  of 
the  triple-action  press  at  S  and  is 
fastened  to  it  by  the  cap-screws 
through  T.  The  combined  cutting 
punch  and  blank-holder  was  a 
forging  of  mild-steel  back  and  tool- 
steel  face,  while  the  drawing  and 
embossing  punch  was  drawn  and 
worked  out  of  a  round  length  of 
annealed  tool  steel.  It  is  secured 
in  the  inner  ram  by  a  key  through 
the  taper  slot. 

It  will  be  understood  that  very 
accurate  work  was  necessary  in 
making  the  tools  and  that  all 
working  parts  were  hardened, 
drawn,  ground,  and  lapped  to  a 
dead  finish  in  order  to  have  the 
work  come  out  as  required. 

The  manner  in  which  the  tools  were  used  to  produce  the  shell 
was  as  follows : 


FIG.  487. 


412  TOOL-MAKING  AND 

The  lower  die  being  fastened  to  the  face  of  the  plunger  D  and 
the  upper  die  with  the  bridge  bolster  to  the  face  of  the  press 
bolster,  the  combined  cutting  punch  and  blank-holder  Pis  located 
on  the  face  of  the  outer  rani  and  the  combined  drawing  and  em- 
bossing punch  in  the  inner  ram.  The  strokes  of  the  two  upper 
rams  of  the  press  are  then  adjusted,  and  the  lower  one  on  which 
the  embossing  die  is  located  is  adjusted  to  almost  meet  the  face 
of  the  embossing  punch  Q  on  its  up -stroke.  All  is  then  ready. 
The  combined  cutting  punch  and  blank-holder  Pis  worked  down- 
ward by  the  outer  ram  of  the  press,  and  travels  slightly  in  ad- 
vance of  the  drawing  and  embossing  punch  Q  which  is  actuated 
by  the  inner  slide,  the  outer  slide  of  the  press  being  so  adjusted 
that  after  its  stroke  has  been  made  it  stops  during  about  one- 
quarter  of  the  rotation  of  the  crank-shaft.  The  blank  is  cut  out 
from  the  sheet  and  held  between  the  annular  pressure  surfaces, 
if  of  the  die  and  P  of  the  punch,  during  the  down  "  dwell"  of 
the  outer  slide.  Now,  while  the  blank  is  held  under  pressure — 
which  has  been  regulated  to  suit  the  special  requirements  of  the 
metal  to  be  drawn — the  drawing  and  embossing  punch  Q  con- 
tinues to  descend,  draws  the  metal  from  between  the  blank-hold- 
ing surfaces,  and  draws  it  into  and  through  the  die  at  I,  the 
drawing  and  embossing  punch  continuing  to  descend  until  the 
shell  has  been  drawn  completely  through  the  drawing  die,  carry- 
ing it  down  uutil  its  lower  surface  meets  the  face  N  of  the  em- 
bossing die — which  corresponds  in  its  function  to  the  solid  bottom 
in  double-action  dies — mounted  on  plunger  D  working  in  sleeve  C 
on  its  up -stroke.  It  is  actuated  by  arrangements  at  the  side  of  the 
press,  motion  being  communicated  through  cams  on  the  end  of  the 
crank-shaft.  Here  the  shell  receives  on  its  face  the  impression  of 
the  design  shown  in  Fig.  485.  On  the  up-stroke  the  finished  article 
is  stripped  from  the  punch  Q  by  the  stripping  edge  X,  and,  the 
press  being  inclined,  the  work  slides  off  at  the  back. 

It  is  surprising  how  much  fine  work  can  be  got  out  of  a 
triple-action  die  in  a  day  of  ten  hours,  and  it  would  pay  any 
manufacturer  who  has  work  of  the  kind  shown  here  to  do  in 
large  quantities,  to  adopt  dies  of  this  construction,  as  any  of  his 
double-action  presses  can  be  arranged  for  them  at  a  small  cost 
compared  with  the  increased  output. 


INTERCHANGEABLE  MANUFACTURING.         413 

In  regard  to  the  making  of  the  dies,  I  might  state  that  they 
are  easier  to  construct  than  those  of  the  single-action  combina- 
tion type  which  are  most  frequently  used  for  such  work.  There 
are  fewer  parts  to  the  triple-action  dies  than  to  the  others,  and 
there  is  less  liability  of  their  getting  out  of  order,  while  the 
hardening  of  the  working  parts  can  be  done  with  the  assurance 
of  success,  and  the  grinding  and  lapping  of  the  hardened  parts 
to  the  finish  sizes  afterward  can  be  done  with  ease.  In  order 
not  to  leave  any  marks  on  the  outside  of  the  shell  when  drawing 
aluminum,  it  will  be  found  well  to  lap  the  drawing  die  after 
grinding  with  a  lap  actuated  in  the  direction  of  the  working 
movement. 

I  neglected  to  state  that  it  was  necessary  to  lubricate  the 
aluminum  sheets  before  working,  but  as  the  cleaning  of  the  cov- 
ers afterward  would  have  cost  more  than  the  making  of  them, 
and  as  the  preparation  which  was  to  fill  the  boxes  was  such  as  to 
require  the  entire  elimination  of  oil  on  the  metal,  we  had  to  be 
very  careful  in  lubricating  the  sheets  so  as  to  get  a  sufficiently 
thin  coating  on  them  to  allow  of  its  being  taken  up  in  the  work- 
ing of  the  metal.  This  was  successfully  accomplished  by  coat- 
ing one  sheet  thickly  with  melted  Eussian  tallow  and  running  it 
through  a  pair  of  rolls,  after  which  a  number  of  other  sheets 
were  run  through  and  coated  evenly  and  thinly.  The  oil  disap- 
peared entirely  during  the  blanking  and  drawing  of  the  shell. 

The  cover  was.  3^  inches  in  diameter,  1  inch  high;  was 
punched  from  stock  slightly  over  -fa  inch  thick  and  required  a 
blank  4'ff-  inches  in  diameter,  which  left  just  the  narrowest  pos- 
sible margin  for  trimming. 

BLANKING   AND   DRAWING   AN    ALUMINUM    SHELL. 

Not  very  long  ago  I  had  a  set  of  dies  to  make  for  the  produc- 
tion of  an  aluminum  box,  and  as  it  was  necessary  to  construct 
the  tools  so  that  the  articles  might  be  produced  at  the  minimum 
of  cost,  I  adopted  dies  which  would  allow  of  producing  a  cover 
and  a  box  complete  at  each  stroke  of  the  press ;  that  is,  one  die 
for  the  cover  and  another  for  the  body  of  the  box.  These  dies 
were  of  the  combination  cutting  and  drawing  type,  in  which  the 


414 


TOOL-MAKING   AND 


blank  is  first  cut  and  then  field  between  the  annular  pressure 
surfaces  of  tfie  puncfi  and  blank-fiolder  ring  wfiile  it  is  being 
drawn  up  into  tfie  puncfi.  Tfie  sfiell  as  drawn  to  form  tfie  body 
of  tfie  box,  and  tfie  die  used  for  it  are  sfiown  in  Fig.  488. 

As  I  fiave  been  in  a  number  of  sfiops  wfiere  tfiey  use  two  dies 
to  accomplisfi  results  wfiicfi  are  attained  in  tfiis  one,  and  as  tfie 


FIG.  488. 

construction  and  action  of  tfiese  dies  are  by  no  means  well  known, 
a  sfiort  description  of  it  may  be  of  interest. 

Fig.  488  shows  a  longitudinal  cross-section  of  tfie  die  com- 
plete as  it  appears  wfien  set  in  tfie  press  and  ready  for  work. 
A  A  is  tfie  cutting-die,  a  forging  of  mild  steel  witfi  a  tool-steel 
face  to  act  as  tfie  cutting-edge ;  G  is  tfie  drawing  puncfi,  wfiicfi 


INTERCHANGEABLE   MANUFACTURING.         415 

is  located  in  the  cutting-die  by  being  screwed  into  a  set  at  E  E ; 
D  is  the  spring-pressure  attachment  plate,  to  which  the  cutting 
die  is  bolted  by  bolts  0  0;  P  P  are  two  of  the  six  tension  pins 
which  support  the  blank-holder  ring  B  B  and  communicate  the 
tension  from  the  rubber  spring  barrel  L.  The  spring-barrel  at- 
tachment consists  of  the  stud  N  which  is  screwed  into  a  tapped 
hole  Jin  the  plate  I)  D,  the  two  cast-iron  washers  A'  K,  and 
the  rubber  spring  barrel  L.  This  rubber  spring  barrel  is  usually 
about  3^  inches  in  diameter  and  6  inches  long,  for  drawing  all 
shells  up  to  one  inch  in  depth.  M  is  the  nut  for  adjusting  the 
pressure  in  the  blank  while  it  is  being  drawn  up  into  the  punch. 

In  the  punch  or  upper  section  of  the  die,  F  Fis  the  combined 
cutting  punch  and  drawing  die.  It  is  a  forging  of  mild  steel 
with  a  tool -steel  ring  welded  on  to  act  as  the  cutting  and  draw- 
ing face.  II  is  the  drawing-die  portion  of  this  punch,  G  the 
spring  pad  which  expels  the  shell  after  it  is  drawn,  and  J  the 
adjusting  nut  for  the  spring  pads.  In  a  die  of  this  kind  the 
cutting  punch,  drawing  pad,  blank-holder  ring,  and  cutting 
die  are  all  hardened  and  tempered,  the  cutting-edges  being 
drawn  to  a  dark  straw  and  the  drawing  portions  to  a  light  straw 
temper. 

In  using  a  punch  and  die  of  this  kind  the  die  is  first  set  up 
on  the  press  bolster  and  the  plate  I)  D  bolted  to  same.  The 
punch  is  then  located  in  the  ram  of  the  press  and  aligned  with 
the  die.  After  this  the  stroke  of  the  press  is  set  so  that  the 
punch  will  descend  the  proper  distance,  the  pressure  of  the 
spring  buffer  is  regulated,  and  we  are  ready  to  proceed.  A  sheet 
of  stock  is  entered  to  rest  on  top  of  the  cutting-die  and  the  press 
stopped.  As  the  press  descends,  the  cutting-edges  punch  the 
blank  into  the  cutting  die  A  A,  where  it  is  held  between  the  faces 
of  the  punch  and  the  blank -holder  ring  jB  B,  and  as  the  punch 
continues  to  descend  the  drawing  punch  G  draws  the  metal  up 
into  the  cutting  punch  and  from  between  the  pressure  surfaces, 
the  metal  being  held  tight  enough  to  prevent  inceptive  wrinkles 
and  crimps  from  forming.  As  the  punch  rises  the  sheet  of  stock 
is  stripped  from  it  by  bent  pins  placed  around  the  cutting-die, 
and  the  finished  shell  is  expelled  from  the  inside  by  the  spring 
pad  0  being  actuated  by  a  knock-out  in  the  press  body.     When 


416  TOOL-MAKING  AND 

a  die  of  this  kind  is  used  to  an  inclined  press  the  finished  shell 
falls  off  through  gravity  at  the  back. 

Combination  cutting  and  drawing  dies  of  the  construction 
shown  and  described  here  may  be  used  to  the  best  advantage  for 
the  production  of  shells  from  stock  as  thin  as  paper  up  to  \  inch 
thick.  They  may  be  used  in  either  single-acting  foot  or  power 
presses.  In  most  cases  the  shells  produced  in  dies  of  this  kind 
are  of  shallow  shapes,  their  edges  frequently  not  being  over 
-3L-  inch  deep,  as  for  instance,  can  tops  and  bottoms,  pail,  bucket 
and  cup  bottoms,  etc.  On  the  other  hand,  however,  dies  of  this 
class  can  be  used  for  the  production  of  much  deeper  articles, 
such  as  boxes  and  covers  for  blacking,  lard,  salve,  and  other 
goods  up  to  f  inch  deep,  or  for  cutting  and  drawing  burner  and 
gas-fixture  parts,  toys,  etc.,  up  to  1  inch  in  depth.  However, 
the  best  results  will  be  secured  in  the  drawiug  of  shells  which 
will  not  exceed  f  inch  in  length,  as  in  order  to  draw  that  depth 
the  rubber  spring  barrel  has  to  compress  to  its  maximum,  and  to 
compress  it  more  would  cause  the  metal  either  to  stretch  exceed- 
ingly or  to  split.  When  it  is  desired  to  draw  shells  over  f-  inch 
in  depth  it  will  be  found  better  to  use  two  dies,  a  combination 
die  and  a  re-drawing  or  finishing  "push -through"  die. 

As  the  die  shown  here  was  for  cutting  and  drawing  alumi- 
num, it  may  be  well  to  assure  my  readers  that  no  difficulty  was 
experienced,  notwithstanding  that  the  tools  were  made  the  same 
as  for  working  brass.  The  precaution  necessary,  however,  to 
assure  satisfactory  results  was  the  use  of  a  proper  lubricant, 
which  was  a  cheap  grade  of  vaseline.  For  deep  draws  in  this 
metal  use  lard  oil. 

A   NICE   JOB   OF   BENDING   AND   FOBMING. 

Fig.  489  shows  the  blank  to  form  Fig.  491.  This  blank  was 
7  inches  long  by  2\  inches  wide,  and  was  of  hard  brass  -^  inch 
thick.  The  corners  were  to  be  sheared  to  the  radius  shown, 
three  holes  were  to  be  pierced  at  each  end,  and  a  slot  was  to  be 
punched  in  the  centre. 

It  was  considered  more  economical  to  shear  the  strips  of 
stock  to  the  required  width.     The  tools,  Fig.  492,  were  of  the 


INTERCHANGEABLE  MAN  UFA  CTURING. 


417 


"gang"  type,  performing  the  operations  on  the  blank  success- 
ively, and  lastly  cutting  off  the  piece  to  the  required  length.  In 
the  die  section  V  V  indicate  two  of  the  piercing  dies.     They  are 


o 

p 

> 

o 

0 

The  Bl'ank 

0 

o 

u 

o 

FiG 

489. 

hardened  and  ground  steel  bushings  let  into  counterbored  seats 
in  the  cast-iron  die-block.  X  is  the  slotting  die  located  in  a 
channel  in  the  face  of  the  die-block  by  means  of  a  strong  dowel 


-After  First  Bending  Operation 


Fig.  491. 


at  Y.  Z  is  the  corner-trimming  and  cutting-off  die,  located  in 
the  die-block  in  the  same  manner  as  the  die  T.  The  gauge-plate 
extends  along  the  entire  length  of  the  die,  while  the  stripping 


g    g 


Plan  of  Punch 


r  'fn'zll        I  W^^l 


J '. ■■','■■■    .;':/,..»      :..      1         !■'■    ■■..■//>■:■>.■>/■*/. 


FIG.  492. 

arrangement  consists  of  four  straps  fastened  by  round -head 
screws  T.  By  making  the  die  in  this  way  any  injured  part 
could  be  taken  out  and  replaced  independently. 

The  punch  consists  of  a  cast-iron  holder  in  which  are  located 

27 


418 


TOOL-MAKING  AND 


all  of  the  small  punches,  five  of  which  are  fastened  in  their  coun- 
terbored  seats  by  means  of  set-screws  J,  while  the  inner  central 
one  is  fastened  by  a  flat-head  screw  let  in  from  the  back  of  the 
holder.  The  slotting  punch  M  is  located  in  a  square  channel  in 
the  holder  by  dowel  0  and  two  flat-head  screws  JV  N.  The 
trimming  and  cutting-off  punch  is  located  in  the  same  manner  in 
channel  Q  Q  by  dowel  B  and  screws  8  8. 

The  slotting  punch  M  is  the  longest,  while  the  cutting-off 
punch  is  the  shortest.  This  is  so  that,  the  stock  being  fed  from 
left  to  right,  the  slotting  punch  will  pierce  the  stock  first  and 


PLAN 

OF 
PUNCH 


FIG.  493. 


locate  it  while  the  six  holes  are  being  pierced,  and  the  cutting-off 
punch  will  not  commence  to  cut  until  all  other  punches  have 
entered  their  dies.  Thus  the  accurate  sizing  of  the  blanks  arid 
the  location  of  the  various  operations  is  assured.  With  this  die 
an  adjustable  stop,  not  shown,  was  used. 

The  result  of  the  first  bending  operation  on  the  blank  is  shown 
in  Fig.  490,  and  to  perform  it  the  tools  shown  in  Fig.  493  were 
used.  The  sketches  are  so  clear  that  very  little  description  will 
be  necessary.  The  punch-holder  is  of  cast  iron  dovetailed  on 
the  face  at  K  K  for  the  punch  of  tool  steel,  which  is  worked  out 


INTERCHANGEABLE  MANUFA  GTTJBING. 


419 


to  the  shape  shown  and  hardened  at  the  bending  face.  The 
locater  0  and  the  spring  arrangement  are  self-explanatory.  The 
die  also  is  of  tool  steel  and  is  machined  to  fit  the  bolster  and  has 
a  tapped  hole  at  W  for  fastening  screw.  P  P  indicate  the  blank 
in  position  for  forming,  while  the  dotted  lines  V  V  indicate  it  as 
formed  into  the  die.  S'S  are  the  side  gauges  and  T  the  end 
locating  point.  In  use,  the  press  in  which  the  dies  were  located 
was  inclined,  and  the  work  after  bending  fell  off  at  the  back. 

For  the  last  operation  in  the  production  of  Fig.  491  the  very 
simple  tools  illustrated  in  Fig.  494  were  used.  The  work  before 
finishing  is  indicated  by  the  dark  portion  0  0  in  position  on  the 


Fig.  494. 


locater  L,  while  the  dotted  lines  P  P  show  it  as  finished.  The 
punch,  of  tool  steel,  is  machined  to  fit  the  dovetailed  channel  in 
the  face  of  the  holder  (not  shown)  and  at  J  J  to  fit  the  central 
formed  section  of  the  work ;  the  die  is  of  cast  iron. 

The  rapidity  with  which  these  two  bending  dies  can  be 
worked  and  the  quality  of  the  work  done  by  them  are  surprising 
when  the  simplicity  and  cheapness  of  the  tools  are  considered. 
Some  may  think  that  it  would  have  been  better  to  have  designed 
a  die  which  would  do  all  the  bending  in  one  operation.  Possi- 
bly, if  a  sufficient  quantity  of  the  articles  were  required — say 
several  millions. 


420 


TOOL-MAKING  AND 


"GANG"   PUNCH   AND   DIE   FOE   PEODUCING 
EYELETS   IN   ONE   OPEEATION. 

As  an  example  of  what  is  being  accomplished  in  the  devising 
of  means  for  the  production  of  sheet-metal  articles  in  one  opera- 
tion I  illustrate  and  describe  here  a  "gang"  die  of  very  interest- 
ing type.  A  number  of  these  dies  were  designed  and  put  into 
successful  operation  by  the  writer  not  long  ago  for  the  produc- 


FlG.  495. 

tion  of  one  of  two  parts  of  a  metallic  button.  They  will  be 
found  the  best  to  adopt' *f or  the  manufacture  of  small  buttons, 
eyelets,  shell  rivets,  and  anything  of  like  nature  that  it  is  neces- 
sary to  produce  cheaply  and  in  large  quantities.  To  secure  the 
minimum  cost  of  operation,  the  stock  is  usually  fed  automatic- 
ally by  means  of  a  fine-tooth  ratchet  roll-feed,  thus  securing  fine 
adjustment  of  the  stroke. 

In  brass  work,  where  we  can  get  our  stock  in  long  lengths, 
or  in  rolls  approximately  uniform  in  width,  a  die  of  the  type 
shown  in  Fig.  495  will  run  off  the  entire  strip  or  roll  without  the 


INTERCHANGEABLE  MANUFACTURING.  421 

possibility  of  error,  thus  allowing  of  the  press  attendant  looking 
after  several  presses  and  keeping  them  running  continually. 

Now,  in  the  first  place,  be  it  understood  that  in  order  to  draw 
sheet  metal  into  any  form  or  shape,  it  is  first  necessary  to  pro- 
vide a  blank.     And  when  the  article  drawn  is  produced  progres- 


FiG.  496. 

sively,  as  in  the  die  here  shown,  it  is  necessary,  first,  to  cut  the 
blank  partty  from  the  strip  so  that  it  may  decrease  in  diameter 
with  the  drawing  in  such  a  manner  as  in  no  way  to  disturb  the 
relative  distance  between  the  centres  of  the  different  operations 
required  to  produce  the  shell.  This  is  the  point  which  many 
die-makers  forget,  so  that  the  dies  prove  defective  where  means 
are  not  provided  for  first  partly  cutting  the  blank,  and  there  is 
no  possibility  of  locating  the  successive  operations  in  their 
proper  positions,  because  of  the  metal  which  goes  to  form  the 
cup  being  drawn  sidewise  and  lengthwise  in  the  first  drawing. 
And  as  this  will  continue  with  each  draw,  .there  will  be  no  likeli- 
hood of  accurately  locating  the  different  operations.  The  way 
in  which  a  "gang"  die  of  this  kind  should  be  made  in  order  to 
attain  the  desired  results,  will  become  apparent  to  the  practical 
reader  in  the  description  of  the  tools  here  shown. 

The  punch  and  die  were  used  to  produce  small  shells  like  the 
one  shown  at  the  upper  right  of  Fig.  495.  And  it  required  seven 
workings  to  produce  the  shell,  finishing  it  complete  from  flat 
stock  at  the  rate  of  40, 000  to  50, 000  per  day  of  ten  hours.  The 
stock  used  was  .  030  soft  brass. 

As  the  illustrations  of  the  die  and  punch  show  clearly  the 
various  parts  used  in  the  construction  of  the  tools,  and  Fig.  496 
the  results  accomplished  at  each  operation  in  the  progress  of  the 
strip  across  the  die  face,  very  little  description  will  be  necessary. 

The  stock  is  first  cut  as  indicated  at  A,  Fig.  496,  by  punch  J, 
Fig.  495,  and  then  at  B  by  punch  K.  Thus,  the  blank  is  pro- 
duced so  as  to  remain  attached  to  the  strip  and  to  allow  of  being 
drawn  and  decreased  in  diameter  by  the  subsequent  operations 


422  TOOL-MAKING  AND 

without  affecting  the  position  of  its  centre  in  relation  to  the 
strip.  This  will  allow  of  the  metal  being  drawn  into  the  shell 
and  still  leave  a  margin  to  hold  the  cups  together  and  allow  of 
feeding  them  along  for  the  next  operation. 

The  stems  of  the  seven  punches  J KL  M N  0  and  P  are  let  into 
reamed  holes  in  the  holder  I  and  are  fastened  with  set-screws, 
not  shown.  The  punches  were  all  hardened,  drawn,  and  care- 
fully lapped  to  size  and  shape.  The  die  is  finished  in  the  usual 
manner,  formed  counterbores  being  used  to  finish  the  drawing 
and  sizing  dies.  Q  is  the  first  cutting  die,  R  the  second,  8  the 
first  drawing  die,  T  the  second,  77  the  third,  and  V  the  sizing 
and  finishing  drawing  die,  while  W  is  the  blanking  and  trimming- 
die.  Each  of  the  drawing  dies  is  furnished  with  a  plunger, 
which  is  hardened  and  drawn  and  let  into  pad  Y.  These  plun- 
gers serve  the  double  purpose  of  holding  the  metal  while  being 
drawn  and  of  stripping  it  from  the  dies  afterward,  thereby  leav- 
ing the  stock  free  to  be  fed  forward  to  receive  the  next  opera- 
tion. A  channel  planed  lengthwise  in  the  bolster  A- A  at  Z 
allows  the  pad  Y  to  work  up  and  down  with  the  action  of  the 
press  ram.  The  two  springs  B-B  B-B  keep  the  plungers  up  with 
sufficient  tension  to  hold  the  metal  securely  between  their  faces 
and  the  faces  of  the  drawing  punches  while  the  drawing  and 
reducing  are  being  accomplished.  Their  pressure  is  adjusted  or 
regulated  by  the  headless  screws  D-D  D-D.  The  trimming  or 
blanking  punch  P  has  a  pilot  pin  which  fits  the  last  drawing 
snugly  and  locates  it  true  and  central  for  being  trimmed  and 
blanked  clean  off  the  strip. 

As  the  results  accomplished  by  the  use  of  such  tools  as  are 
herein  described  and  illustrated  would  require  three  or  more 
operations  if  the  simpler  tools  were  used,  it  is  no  hard  matter  to 
figure  out  what  the  saving  is. 

In  conclusion  I  might  state  that  there  is  any  variety  of  small 
drawn,  formed,  or  embossed  sheet  metal  work  that  could  be  pro- 
duced more  accurately  and  in  half  the  time  by  the  use  of  just 
such  dies  as  that  shown  here.  In  order  to  succeed  with  these 
tools,  however,  always  remember,  before  attempting  to  draw  and 
form  cups  progressively  from  the  strip,  to  provide  means  for 
partly  cutting  the  blanks  from  which  to  draw  the  cups. 


INTERCHANGEABLE  MANUFACTURING. 


423 


COMPOUND   DIES  FOR  PARTS   OF  TELEPHONE 
TRANSMITTER  CASES. 


FIG.  497. 


In  Fig.  497  are  shown  the  assembled  parts  of  a  telephone 
transmitter  case  of  sheet  metal,  and  in  Figs.  498  to  503  the  dies 
used  .for  producing  the  parts.  It  is  needless  to  state  that  these 
cases  are  used  in  great  quantities  and  that  the  dies  for  their  pro- 
duction are  required  to  be  of  the 
most  accurate  and  lasting  con- 
struction in  order  that  the  parts 
may  be  produced  rapidly  and  in 
exact  duplication.  As  the  work 
involved  in  the  production  of  the  R 
transmitter-case  parts  consists  of 
blanking,  drawing,  forming,  pierc- 
ing, and  wiring,  the  dies  are  in- 
teresting, and  engravings  of  them, 
together  with  the  description  of 
their  construction  and  operation, 
will  prove  suggestive  in  the  adoption  of  similar  tools  for  the 
production  of  a  large  variety  of  drawn  sheet-metal  work,  accu- 
rately and  economically. 

As  will  be  seen  from  Fig.  497,  the  case  consists  of  three  parts, 
designated  1,  2,  and  3,  respectively.  The  part  1  is  of  an  artistic 
shape  and  represents  a  nice  job  in  drawn  work.  The  die  used 
for  producing  it  is  shown  in  Fig.  498  and  was,  as  were  all  the 
blanking  and  drawing  dies  used  in  the  production  of  the  case 
parts,  of  the  compound  double-action  type  of  construction.  As 
a  great  many  tool-makers  are  not  familiar  with  drawing  dies  of 
this  type,  a  slight  description  of  their  use  will  contribute  to  an 
intelligent  understanding  of  their  making. 

Double-action  dies  derive  their  name  from  the  fact  that  they 
are  used  in  double -action  presses  to  cut  a  blank  and  at  the  same 
stroke  draw  it  into  shape  without  the  help  of  springs  or  buffers, 
as  in  the  case  combination  single-action  dies.  The  kind  and 
thickness  of  the  metal  used  determine  whether  one  or  several 
operations  will  be  necessary  to  obtain  the  desired  shape  and 


424 


TOOL-MAKING  AND 


depth  in  the  article.  There  are  two  essentially  different  types 
of  double-action  dies,  viz.,  Fig.  498  is  a  "solid -bottom  die,"  and 
Fig.  501  a  "push-through  die."  However,  they  are  both  used 
in  the  same  way. 

Taking  the  die  Fig.  498 — which  was  used  for  producing  the 
part  1  of  Fig.  497 —  G  is  the  die  bolster,  in  which  the  drawing 
and  blanking  dies  are  located.  It  will  be  understood  that  all 
parts  of  this  die  had  to  be  constructed  very  accurately,  that  the 
working  x>arts  were  hardened,  drawn,  and  ground  and  lapped 
smooth  in  order  to  produce  the  parts  as  required.    In  the  die,  A 


Fig.  498. 

is  the  main  drawing  die,  which  is  located  in  a  taper  seat  in  the 
bolster,  while  F  F  is  the  blanking  die,  located  in  a  seat  in  the 
surface  of  the  bolster  and  secured  by  means  of  the  two  fillister 
head-screws  H  H.     N  is  a  stripper  of  the  usual  type. 

In  the  punch  section,  L  L  is  the  combined  cutting  punch  and 
blank-holder ;  a  forging  of  mild  steel  with  a  tool-steel  ring  welded 
on  to  oiie  side  to  act  as  the  cutting  punch  1 1.  It  was  machined 
all  over;  being  turned  at  J  J  to  locate  on  the  face  of  the  outer 
ram  of  the  double-action  press,  and  was  hardened  and  drawn  at 
1 1  and  then  ground  to  fit  the  cutting  die  F  F,  after  which  the 


INTERCHANGEABLE  MANUFACTURING.         425 


face  was  lapped  so  that  the  blank  would  be  held  evenly  while 
being  drawn.  B  is  the  drawing  and  forming  punch  and  E  its 
stem.  The  maimer  in  which  this  die  was  used,  as  well  as  the 
other  double-action  dies  shown  here,  will  be  understood  from 
the  following : 

The  lower  or  die  section  G  is  fastened  to  the  face  of  the  press 
bolster,  while  the  combined  cutting  punch  and  blank-holder  1 1 
is  fastened  to  the  face  of  the  outer  ram,  and  moves  slightly  in 
advance  of  the  drawing  punch  B,  the  stem  A"  of  which  is  fastened 
in  the  inner  ram,  by  which  it  is  actuated.     The  outer  ram  of  the 


Fig.  499. 

double-action  press  being  so  arranged  that,  after  making  its- 
stroke,  its  stops  during  about  one-quarter  revolution  of  the 
crank-shaft,  and  the  combined  cutting  punch  and  blank-holder 
cuts  the  blank  at  F  F,  carries  it  down  to  the  inner  surface  of  the 
cutting  die ;  holds  it  there  tightly  and  remains  stationary,  hold- 
ing it  between  the  annular  pressure  surfaces  of  the  punch  and 
E  E  during  the  down  "dwell"  of  the  outer  slide. 

While  the  blank  is  under  a  pressure  which  has  been  regulated 
to  suit  the  special  requirements  of  the  case,  the  drawing  punch 
B  continues  its  downward  movement,  thus  drawing  the  metal 
from  between  the  pressing  surfaces  into  the  shape  required.  As 
the  punch  rises  the  combined  blank-holder  and  cutting  punch 
remains  stationary  until  the  drawing  punch  has  disappeared 
within  it ;  then  it  rises  also.  At  the  completion  of  the  up -stroke 
a  knock-out  attached  to  the  press  actuates  the  die  knock-out  D 
which  delivers  the  finished  shell  at  the  top  of  the  die.     Some 


426 


TOOL-MAKING  AND 


very  close  work  and  careful  grinding,  lapping,  and  polishing 
were  necessary  in  order  to  get  this  die  to  produce  part  1  as  was 
desired,  the  metal  used  being  sheet  brass  y1^  inch  thick,  the  utmost 
care  being  necessary  to  get  the  difference  in  the  diameter  and 
curves  and  shape  of  the  punch  and  die  exactly  two  thicknesses 
of  metal. 

The  punch  and  die  used  for  producing  part  2  of  Fig.  497  is 
shown  in  Fig.  500.  Although  a  compound  double-action  die,  it 
will  be  seen  that  it  is  constructed  differently  from  the  one  shown 
in  Fig.  498,  and  that  different  results  are  accomplished  in  it.  In 
this  die  the  shell,  forming  part  2  of  Fig.  497,  is  blanked,  drawn, 
formed,  and  a  hole  pierced  in  the  centre,  to  admit  the  end  of  part 


3  as  shown  at  a,  Fig.  497,  at  one  stroke  of  the  press.  However, 
the  use  and  operating  of  the  die  are  the  same  as  explained  for  the 
first.  As  in  the  other,  close  and  careful  work  were  necessary 
on  all  the  parts  in  order  to  have  the  die  work  well  in  the  press. 
In  the  die  section,  B  E  is  the  cast-iron  bolster,  P  P  the  combined 
cutting  and  drawing  die,  and  Q  Q  the  combined  bottom-forming 
and  hole-piercing  die. 

In  the  upper  section  of  die,  Fig.  500,  W  W  is  the  combined 
cutting  punch  and  blank-holder,  a  forging  T  T  the  drawing  and 
forming  punch,  and  Z7the  hole-piercing  punch.     The  manner  in 


INTERCHANGEABLE  MANUFACTURING. 


427 


which  the  metal  is  cut,  drawn,  formed,  and  the  hole  pierced, 
may  be  seen  from  the  dark  section.  In  this  die  the  bottom-form- 
ing and  hole-piercing  die  Q  Q  also  acts  in  the  capacity  of  a 
knock-out ;  it  being  actuated  on  the  up-stroke  of  the  press  rams  by 
the  knock-out  device  attached  to  the  press.  The  blank  produced 
by  the  hole-piercing  punch  U  fiuds  egress  through  an  enlarged 
hole  running  entirely  through  the  stem  of  the  piercing-die  sec- 
tion. Ideal  results  may  be  accomplished  in  a  die  of  this  con- 
-struction,  as  the  holding  of  the  blank  while  it  is  being  drawn  is 
perfect ;  an  even  pressure  being  maintained  all  the  time,  which 
is  not  the  case  when  single-action  combination  dies  are  used,  as 
the  tension  on  the  blank  is  communicated  through  a  rubber 
spring  barrel  which  compresses  as  the  blank-holder  ring  de- 
scends and  thus  renders  the  tension  uneven.     Thus,  deep  draws 


Fig.  501. 


cannot  be  attained  in  a  single-action  die  through  the  metal  tear- . 
ing  or  splitting  because  of  too  much  pressure  on  the  blank  as 
the  draw  nears  completion ;  while  in  compound  double-action  or 
triple-action  dies,  draws  of  considerable  depth,  in  comparison 
with  the  diameters,  can  be  attained  because  the  pressure  on  the 
metal  is  exerted  by  cams  on  the  crank -shaft  and  is,  of  course, 
even. 

To  produce  part  3  of  the  case,  to  the  shape  shown  in  Fig.  497, 
three  operations  were  necessary.     The  first  consisted  of  drawing 


428 


TOOL-MAKING   AND 


a  shell  of  the  shape  shown  at  the  upper  left  of  Fig.  501.  This 
shell  was  blanked  and  drawn  in  the  double-action  "push- 
through  "  die  shown  in  Fig.  501.  As  will  be  seen,  the  die  sec- 
tion is  in  one  piece.  It  was  a  forging  of  mild  steel  at  base,  with  a 
tool -steel  face  for  the  cutting  die.  The  weld  of  the  two  steels  is 
indicated  by  a  wavy  line  in  the  drawing.  The  machining  and 
finishing  of  the  die  were  accomplished  in  the  usual  manner;  all 
working  parts  being  left  over  size,  and  ground  and  lapped  to  a 


Fig.  502. 


finish  after  the  die  had  been  hardened  and  tempered.  A  is  the 
base,  C  C  the  cutting  die  and  blank-holder  portion,  D  D  the 
drawing  die,  and  B  B  the  stripping  edge. 

In  the  punch  section  of  Fig.  501,  H  is  the  combined  cutting 
punch  and  blank-holder  and  J  the  drawing  punch.  As  will  be 
seen,  the  die  is  equipped  with  a  stripper  of  the  usual  construc- 
tion. This  die  was  a  far  more  rapid  producer  than  the  other 
two,  as  the  metal  was  cut,  then  drawn  and  pushed  through  the 


INTERCHANGEABLE  MANUFACTURING.  429 

die,  stripping  at  B  B ;  thus  obviating  the  necessity  of  a  knock- 
out and  the  delivering  of  the  drawn  shell  at  the  top  of  the  die. 

The  second  operation  in  the  production  of  part  3  was  accom- 
plished by  means  of  the  tools  shown  in  Fig.  502.  These  tools 
require  little  description  as  their  construction  and  use  are  al- 
most evident  at  a  glance.  S  is  the  punch -holder,  P  the  drawing- 
punch,  and  R  its  stem;  while X is  the  inside  blank-holder  which 
supports  and  holds  the  shell  on  the  inside  while  it  is  being  reduced 
and  formed;  Q  is  the  stripper.  In  the  die,  L  is  the  bolster,  M 
the  die,  and  iVthe  knock-out  for  stripping  the  finished  work  from 
the  die.  The  punch  and  die  were  operated  in  a  reducing  press 
with  a  stroke  of  considerable  length. 

The  last  operation  in  the  production  of  part  3  consisted  of 
punching  out  the  bottom  at  &  &  and  wiring  the  edge  at  d  d  as 
shown.  This  work  was  accomplished  entirely  by  the  use  of 
the  combination  wiring  and  piercing  die  shown  in  Fig.  503. 
Although  the  drawing  is  very  clear,  a  description  may  assist 
many  to  understand  intelligently  the  construction  and  working 
of  the  tools. 

In  the  lower  section,  T  is  a  cast-iron  bolster,  bored  out  and 
recessed  for  the  hole-piercing  die  U  Z7and  the  holder  and  locator 

V  V.  The  piercing  die  was  of  tool  steel,  hardened,  ground,  and 
lapped  to  size,  and  a  force-fit  into  its  seat  in  the  bolster,  while 

V  V  was  of  mild  steel  worked  out  on  the  inside  to  fit  the  formed 
shells  and  turned  taper  on  the  outside  to  drive  into  the  taper  seat 
in  the  bolster. 

The  upper  section  consists  of,  first,  the  holder  B,  a  forging  of 
mild  steel  worked  and  machined  as  shown,  to  contain  the  wiring 
die  W  W,  the  spring  stripper  and  work  supporter  X  X,  and  the 
piercing  punch  T.  As  will  be  seen,  the  wiring  die  is  located  in 
a  seat  in  the  holder-face  and  fastened  by  means  of  fillister  head, 
screws,  while  the  piercing  punch  is  located  in  a  reamed  hole  run- 
ning entirely  through  the  holder,  and  is  permanently  secured  in 
position  by  means  of  a  taper  pin  at  A.  The  spring  D  D  exerts 
enough  pressure  on  the  combined  work-supporter  and  stripper 
X  X  to  allow  of  it  supporting  the  shell  on  the  inside  while  it  is 
being  wired  by  the  die  W  W,  and  then  stripping  it  from  the 
piercing  punch  at  the  rise  of  the  press  ram. 


430 


TOOL-MAKING   AND 


When  the  punch  and  die  are  in  use,  the  shell  is  slipped  into 
the  locating  seat  in  V  V  and  the  press  stepped.  As  the  punch 
descends,  the  supporter  and  stripper  come  in  contact  with  the 
inside  of  the  shell  and  hold  it  tightly  while  the  spring  com- 
presses and  the  rest  of  the  punch  parts  continue  to  descend. 
Then  the  edge  of  the  shell  enters  the  wiring  groove  and  follows 
around  its  curves ;  the  punch  descending  until  the  curl  is  com- 
plete, the  piercing  punch  T  having  meanwhile  punched  the  bot- 
tom out  of  the  shell  and  into  the  die  77.  At  the  up -stroke  of  the 
ram  the  stripper  X  X  remains  stationary  until  the  piercing  punch 


Fig.  503. 


has  left  the  shell  and  the  wiring  die  has  risen  above  it ;  then  it 
rises  also,  leaving  the  finished  shell  in  a  position  to  be  easily 
removed. 

The  other  operations  necessary  to  allow  of  the  parts  of  the 
transmitter  case  being  assembled  as  shown  in  Fig.  497  consisted 
of  joining  parts  3  and  2  together  as  shown,  and  piercing  four 
holes  in  the  rims  of  parts  1  and  2  for  screws.  But  as  the  tools 
used  for  those  latter  operations  were  very  simple,  their  illustrat- 
ing and  describing  are  unnecessary. 

In  conclusion,  I  might  state  that  it  would  be  well  for  manu- 


INTERCHANGEABLE  MANUFACTURING.         431 

facturers  of  artistic  drawn  sheet -metal  articles  and  parts  to  give 
more  attention  to  the  use  of  double-action  dies  and  double-action 
presses,  as  the  results  accomplished  by  their  use  are  not  to  be 
compared  with  those  accomplished  by  combination  dies  in  single- 
action  presses. 


CHAPTER  XXVII. 

Processes,  Presses,  Devices,  and  Arrangements  for 

the  Rapid  and  Economical  Manufacture 

of  Sheet-Metal  Articles. 

PBESS   WOEK. 

It  is  only  during  the  past  few  years  that  the  use  and  value  of 
the  power  press  and  hydraulic  press  for  sheet-metal  working  have 
come  to  be  almost  universally  appreciated  and  known,  and  to-day 
the  rapidity  with  which  their  use  is  being  extended  is  astonishing. 

Among  the  machine-tool  brood  the  power  press  and  its  work 
occupy  a  unique  position  in  one  respect,-  as  it  is  the  only  ma- 
chine tool,  and  its  operation  involves  the  only  process,  in  which, 
after  the  material  is  once  cut  off  from  the  sheet  or  bar,  there  is 
no  making  of  chips  or  waste.  The  press,  as  such,  does  neither 
cutting  or  abrading. 

To  be  sure,  the  power  press  is  usually  a  more  or  less  expen- 
sive machine,  and  the  devising  and  constructing  of  suitable  dies 
for  it  requires  the  employment  of  the  most  skilful  mechanics  and 
is  often  among  the  most  expensive  work  of  the  trade.  But  when 
the  machine  and  dies  are  in  successful  operation  the  saving  of 
labor  in  production  is  enormous,  and  is  greater  than  that  saved 
by  any  other  machine  tool.  In  fact  the  most  elaborate  and  costly 
articles  are  often  numerously  produced  by  the  power  press,  which 
could  not  be  made  by  other  processes  for  one  hundred  times  or 
even  one  thousand  times  the  cost. 

Until  lately  the  power  press,  by  reason  of  its  rapidity  of  pro- 
duction and  the  manifolding  of  its  product,  was  distinctly  a  fac- 
tory machine.  But  to-day  this  same  machine  is  employed  almost 
universally  in  up-to-date  machine  shops  for  the  production  of  an 
endless  variety  of  parts  which  are  used  on  machines,  and  it  is  to 
be  reckoned  with  the  same  as  the  other  machine  tools ;  that  is,  as 
an  economic  producer  of  shop  products. 

432 


INTERCHANGEABLE  MANUFACTURING.         433 

PERFORATING  FLAT   AND   CYLINDRICAL  SHEET 

METAL. 

In  the  production  of  plates  and  articles  with  numerous  per- 
forations, dies  accompanied  by  novel  mechanical  devices  play  a 
more  important  part  than  any  other  line  of  sheet-metal  work. 
While  the  dies  used  in  such  work  are  comparatively  simple,  the 
devices  and  appliances  used  in  connection  with  them  are  often 
intricate  and  novel.  Especially  is  this  so  in  the  perforation  of 
cylindrical  articles  and  parts,  where  the  die  remains  stationary 
and  the  shell  is  rotated  successively  at  each  stroke  of  the  press, 
until  the  entire  surface  has  been  worked  upon.  By  means  of 
these  rotating  devices  shells  may  be  perforated  in  any  design  or 
pattern  of  perforations  by  means  of  a  single  row  of  dies,  the 
manner  in  which  the  shell  is  rotated  after  each  stroke  determin- 
ing the  pattern  of  the  perforations.  Anyone  who  has  noticed 
the  odd,  novel,  and  artistic  designs  in  the  perforated  shells  used 
on  gas  and  lamp  burners  and  fixtures  must  have  wondered  how 
they  can  be  produced  so  cheaply.  The  secret  lies  principally  in 
the  devices  used  for  rotating,  and  farther  on  I  show  a  number  of 
such  devices  and  the  dies  and  tools  used  with  them. 

In  the  perforating  of  flat  sheets  of  metal  the  construction  of 
the  dies  used  is  equally  similar  to  that  followed  out  in  the  "gang  " 
types,  and  they  are  used  on  work  ranging  from  ornamental  sheet- 
metal  articles  to  the  punching  of  holes  in  steel  beams  and  boiler 
plates.  The  holes  pierced  with  this  type  may  be  of  any  shape 
desired  and  may  be  spaced  in  any  manner  or  combinaton.  Often 
the  usual  conditions  are  reversed  and  instead  of  the  perforations 
being  desired,  small  blanks  are  the  objects  sought,  a  number  of 
them  being  fed  to  the  dies  automatically.  Perforated  sheets  of 
the  different  metals  are  now  in  great  demand  and  are  used  for  a 
variety  of  purposes  too  numerous  to  mention. 

ATTACHMENTS   FOR    CYLINDRICAL   PERFORATING. 

In  Fig.  504  is  shown  a  horizontal  two-slide  foot  press  for 
punching  simultaneously  two  holes  or  slots  on  opposite  sides  of 

drawn  shells.     The  die  is  located  in  the  centre  and  is  made  with 

28 


434 


TOOL-MAKING  AND 


cutting-edges  on  opposite  sides  and  with  a  clearance  hole  through 
the  bottom  as  an  escape  for  the  scrap  or  punchings.  The  punches 
are  of  steel  rod  fastened  in  punch-holders  or  chucks  which  are 
adjustable  and  mounted  on  slides  provided  with  adjustable  gibs. 
Each  slide  is  arranged  with  an  adjustable  stop  to  allow  of  pierc- 
ing shells  of  different  diameters.  Dies  of  this  type,  when  used 
in  a  machine  of  the  kind  shown,  are  very  convenient  for  rapidly 
and  accurately  producing  pierced  shells  for  lamp-burners,  satchel 
locks,  and  a  variety  of  other  pierced  work  recpiiring  holes  pierced 
on  opposite  sides. 

Figs.  505  and  506  show  two  different  sets  of  perforating  fixtures 
in  position  on  presses  for  perforating  burner  shells  and  other 


Fig.  504. 


FIG.  505. 


cylindrical  sheet-metal  articles.  Fixtures  of  these  types  are  used 
extensively  for  work  which  it  is  desired  to  perforate  all  around, 
although  sometimes  used  to  perforate  in  sections  only. 

The  attachment  shown  on  the  press  in  Fig.  505  is  used  for 
taper  and  crowning  shells,  which  necessitates  the  setting  of  the 
die-holder  and  rotating  device  at  an  angle  with  the  lower  face  of 
the  slide.  The  shell,  as  perforated,  is  shown  on  press  bolster  at 
the  right. 

Fig.  506  shows  a  press  equipped  with  dies  and  fixtures  for 
perforating  small  close  patterns  in  bottomless  shells.     As  will 


INTERCHANGEABLE  MANUFA CTUBING. 


435 


be  seen  from  the  engraving,  in  which  a  die,  punch,  and  two  per- 
forated shells  are  shown  on  the  floor,  the  die  is  a  piece  of  steel 
with  two  rows  of  holes  in  it  and  dovetailed  into  the  work-holder, 
while  the  punch  is  equipped  with  a  spring  stripper  and  two  rows 
of  piercing  punches.     The  dies  shown  located  in  the  press  are 


Fig.  506. 

for  perforating  the  small  shell,  and  the  ones  on  the  floor  for  per- 
forating the  large  one  shown  at  the  right  at  the  bottom. 

In  the  attachments  of  the  types  shown  in  Figs.  505  and  506 
the  perforating  dial  with  a  chuck  of  suitable  shape  is  mounted 
on  a  die-holder,  and  a  ratchet  having  teeth  spaced  to  suit  the 
holes  or  pattern  desired  is  mounted  and  arranged  to  rotate  the 
shell  at  each  stroke  of  the  press.     By  the  use  of  such  attach- 


436 


TOOL-MAKING   AMD 


meiits,  perforating  may  be  done  at  the  rate  of  150  to  200  strokes 
per  minute. 

The  adjustment  of  the  parts  of  these  perforating  attachments 
is  easily  and  quickly  made,  so  that  but  a  short  time  is  required 
to  change  the  attachments  from  one  style  of  shell  to  another. 
Presses  in  which  such  attachments  are  used  are  often  provided 


FIG.  507. 


with  a  latch  lock  for  the  clutch  connection,  which  is  automatic- 
ally released  after  each  complete  rotation  of  the  article  on  the 
perforating  chuck,  thus  stopping  the  press  automatically  after 
the  requisite  number  of  strokes  have  been  made. 


INTERCHANGEABLE  MANUFACTURING.         437 


PIEBCING   AND   BLANKING   SMALL   ABMATUBE 

DISKS. 

In  Fig.  507  is  shown  a  set  of  dies  as  located  in  an  adjustable 
press  for  accurately  piercing  and  blanking  armature  disks  for 
small  generators  and  motors.  The  press  is  furnished  with  an 
automatic  knock-out,  and  its  inclined  position  allows  the  blank, 


Fig.  508. 

after  being  punched  and  pierced,  to  be  lifted  out  of  the  die  and 
slid  off  at  the  back.  The  pierced  blanks  are  usually  punched 
from  strips  sheared  to  the  necessary  width.  The  construction  of 
the  dies  is  such  as  to  allow  the  outside  and  the  inside  to  be 
punched  simultaneously,  after  which  it  is  held  between  the  faces 
of  the  blanking  punch  and  the  pad,  and  descends  far  enough  for 
the  piercing  punches  located  around  the  die  to  pierce  holes. 
The  fiuished  disks  are  shown  beneath  the  press. 


438  TOOL-MAKING  AND 

KEEPING    SHEETS    OE    AETICLES    STEAIGHT   WHILE 
PEEFOEATING. 

For  perforating  articles  of  considerable  size,  or  flat  plates 
which  are  required,  to  be  kept  straight,  dies  of  the  usual  con- 
struction will  not  do  good  work,  as  on  such  dies  stationary  strip- 
pers are  used  and  they  are  liable  to  distort  the  metal  to  such  an 
extent  as  to  require  subsequent  straightening.  To  overcome  this 
defect  a  press  equipped  with  a  cam -actuated  stripper  should  be 
used,  especially  on  accurate  work,  such  as  parts  of  clocks,  elec- 
trical instruments,  etc.  A  press  equipped  in  this  manner  is 
shown  in  Fig.  508.  The  stripping  device  is  such  as  to  leave  a 
clear  space  between  the  punch  and  die,  thus  allowing  the  oper- 
ator to  manipulate  and  observe  the  work  at  will.  The  action  of 
the  stripper  when  the  press  is  running  is  as  follows :  The  strip- 
per plate  strikes  the  blank  or  article  first,  straightening  and 
clamping  it  before  the  punches  enter,  and  holding  it  under 
pressure  while  the  punching  and  stripping  are  being  accom- 
plished. In  this  manner  the  flat  or  formed  piece  comes  out  per- 
fectly straight  and  true.  The  punches  used  when  a  press  is 
equipped  with  a  stripper  of  this  type  may  be  made  considerably 
shorter  than  where  a  die  with  a  stationary  stripper  is  used,  thus 
making  them  more  durable.  Also  by  this  arrangement  a  smaller 
hole  in  proportion  to  the  diameter  of  the  punches  may  be  pierced, 
through  the  support  given  the  punches  by  the  movable  stripper 
up  to  the  point  where  they  enter  the  stock. 

PEBFOEATING   LAEGE   SHEETS   OF   METAL   IN" 
SPECIAL  DESIGNS. 

For  the  perforating  of  large  sheets  of  metal  in  designs  simi- 
lar to  those  shown  in  Figs.  509,  510,  and  511,  special  feeding 
arrangements  are  used.  Some  of  the  patterns  are  staggered  and 
others  are  regular,  and  to  produce  them  a  single  row  of  "gang" 
punches  and  dies  or  a  double  row  is  used.  When  a  double  row 
or  "gang"  of  punches  and  dies  is  used,  the  metal  is  usually  fed 
automatically  by  means  of  a  roller  feed  to  a  press  of  large  and 
powerful  construction.     The  construction  of  the  punches  and 


INTERCHANGEABLE  MANUFA  CTUBING. 


439 


dies  for  such  work  is  such  as  to  allow  of  removing  any  one  or  a 
number  without  disturbing  the  others.  The  punches  are  usually 
located  in  a  cast-iron  holder  which  is  fitted  to  a  dovetailed  chan- 
nel in  the  face  of  the  press  ram.  They  are  short  and  stocky  and 
fastened  by  set-screws.  The  dies  are  usually  tool-steel  bushings, 
hardened  and  ground,  and  let  into  holes  drilled  and  reamed  in  a 
bolster  of  similar  make  to  that  used  for  the  punches.  The  bush- 
ings also  are  fastened  by  set-screws.     With  a  powerful  press 


Fig.  509. 


Fig.  510. 


Fig.  511. 


equipped  with  proper  feeds  and  punches  and  dies  the  author  has 
seen  154  f -inch  holes  punched  in  ^-inch  plate  at  each  stroke  of 
the  press.  The  press  referred  to  was  used  in  the  works  of  a 
large  agricultural  machinery  concern  and  was  provided  with  a 
roller  feeding  attachment  consisting  of  four  adjustable  rolls,  6 
inches  in  diameter  and  54  inches  long,  which  fed  the  stock  auto- 
matically in  multiples  of  sixteenths  of  an  inch  up  to  four  inches. 
For  heavy  work  the  press  was  provided  with  back  gears,  which 
were  thrown  out  when  doing  light  work,  so  as  to  give  the  press 
a  higher  speed.  The  slide  adjustment  on  this  press  was  such  as 
to  allow  of  raising  or  lowering  it  to  overcome  the  shortening  of 
the  punches  through  wear. 


PEODTTCTION   OF  PEEFOEATED   METAL   BY   THE 
ALLIS-CHALMEES   COMPANY. 

One  of  the  largest  producers  of  perforated  metal  in  the  world 
is  the  Allis- Chalmers  Company,  of  Chicago.  In  their  shops  im- 
proved machinery  is  being  constantly  provided  for  the  produc- 
tion of  perforated  metal  in  the  endless  varieties  which  modern 
demands  necessitate.     The  chief  aim  in  this  plant  is  to  produce 


440 


TOOL-MAKING   AND 


the  material  at  the  lowest  cost  and  in  the  shortest  time  possible. 
This  object,  of  course,  can  be  attained  only  by  keeping  the 
machines  constantly  producing  perforated  sheets  of  the  same  de- 
sign and  pattern.  Most  of  the  output  in  this  line  produced  in 
the  above-mentioned  shops  is  used  for  rotating  screens  for  stone, 
grain,  coal,  ore,  etc. ,  the  perf orated  plates  being  rolled  to  exact 
diameters  in  special  machines.  For  such  purposes  perforated 
metals  have  superseded  and  are  far  superior  to  wire  cloth ;  being 
much  stronger,  more  uniform  in  size  of  hole  and  mesh,  less 
liable  to  tear  or  rust  out,  and  in  case  of  breakage  they  may  be 
easily  repaired  or  replaced  without  affecting  the  entire  sheet.  In 
screens  for  various  purposes  it  is  often  desirable  to  arrange  them 
with  portions  left  blank.  This  can  be  easily  done  when  perfor- 
ated metal  is  used,  as  the  sheets  can  be  perforated  in  a  press 
equipped  with  a  feed  which  can  be  adjusted  to  feed  unequal 
spacings. 

HORNING   AND   SEAMING  PROCESSES. 

In  the  manufacturing  of  pieced  sheet-metal  ware,  the  proc- 
esses of  "horning"  and  "seaming"  play  a  very  important  part, 


Fig.  512 


and  a  large  variety  of  ingenious  devices  and  fixtures  is  used,  giv- 
ing rapid  and  accurate  results.  The  processes  are  essentially 
assembling  and  preparing  ones,  as  they  assemble  flat,  round,  and 


INTERCHANGEABLE  MA MUFA  CTURING. 


441 


irregular  parts,  and  often  prepare  them  for  subsequent  opera- 
tions of  wiring,  curling,  etc.  The  successive  stages  of  a  "lock" 
seam  are  shown  in  Fig.  512  and  a  press  equipped  with  the  tools 
in  Fig.  513.  The  manner  in  which  an  inside  or  an  outside  seam 
is  finished  is  shown,  two  blows  being  necessary  for  each.  The 
first  operation  is  the  forming  of 
the  hooks,  and  the  second  the 
crushing  down  and  locking  to- 
gether. There  is  a  large  variety 
of  work  which  requires  finishing 
with  locked  seams  of  this  kind. 

For  the  double -seaming  of 
bottoms,  tops,  and  parts  of 
round  bodies  together,  the  work 
is  accomplished  by  special  ma- 
chinery and  dies  are  dispensed 
with.  A  machine  for  this  work 
is  shown  in  Fig.  514  and  dia- 
grams of  the  work  done  on  it 
in  Figs.  515  and  516.  These 
machines  are  used  extensively 
for  double  seaming  "flat  bot- 
toms" on  to  tea-kettles,  coffee- 
pots, pails,  and  similar  goods  in  the  tin  and  enamelled  iron- 
ware line. 

The  lower  spindle  carrying  the  "inside  chuck  or  roller  "is 
mounted  on  a  sliding  plate,  which  is  drawn  forward  for  putting 
on  and  taking  off  the  articles.  In  the  case  of  flaring  pails,  dish- 
pans,  and  other  articles  which  are  smaller  at  the  bottom  than  at 
the  top,  the  double  seaming  is  done  against  a  solid  plate  of  the 
size  of  the  bottom,  mounted  on  the  sliding  spindle.  For  buckets, 
cups,  and  other  straight  articles  collapsible  chucks  are  used. 
These  chucks  are  so  made  that  they  spread  to  fit  along  the  edge 
of  the  bottom  when  the  article  is  carried  up  against  the  upper 
chuck,  and  fold  together  after  the  work  is  done  to  permit  the 
rapid  and  easy  removal  of  the  seamed  article. 

For  double-seaming  bottoms  or  tops  stamped  or  drawn  with 
a  burred  edge,  as  per  Fig.  517  and  518,  a  fixture  called  a  deflect- 


FiG.  513. 


442 


TOOL-MAKING  AND 


ing  device  is  required  and  may  be  readily  attached  to  the  ma- 
chine. The  diagrams  show  the  steps  in  which  the  seaming  is 
done;  the  deflecting  device  performs  the  second  of  the  three 


Fig.  514. 


INTERCHANGEABLE  MANUFA CTUBING. 


443 


operations.  The  use  of  burred-edge  blanks  for  the  bottoms  of 
round  work  offers  the  advantage  of  easily  centring  the  bottoms 
on  the  bodies.  For  a  great  many  articles,  however,  plain  bot- 
tom blanks  are  preferred.  In  that  case  the  deflecting  device  is 
dispensed  with,  and  instead  of  it  two  brackets  are  attached  to  the 


Fig.  516. 


machine,  carrying  three  adjustable  rolls  for  centring  the  blanks 
or  bottoms  on  the  bodies,  before  clamping.  For  heavy  stock  it 
becomes  necessary  sometimes  to  have  a  slight  depression  in  the 


First  Step 


Burred  Edge  Top 


f 


7 


Fig.  517. 


Fig.  518. 


centre  of  the  bottom  blank  corresponding  with  a  slight  projec- 
tion on  the  clamping  plate,  so  as  to  prevent  the  pressure  of  the 
seaming  rolls  from  pushing  the  bottom  away  from  its  central 
position. 

For  a  certain  kind  of  work  a  press  specially  equipped  with 
an  automatic  fixture  for  double  horning  or  seaming  is  used.  By 
means  of  this  automatic  fixture  the  two  corner  seams  on  large 
square  cans  having  round  corners  with  seams  in  the  centre,  may 
be  closed  at  one  blow.  Tins  with  sharp  corners  require  a  "  coax- 
ing "  operation  on  a  single  horn  to  start  the  seam  over  before 
setting  over  on  a  double-horn  press.     The  horn,  which  is  movable 


444 


TOOL-MAKING   AND 


in  ways,  has  two  working  surfaces,  the  upper  one  being  acted 
upou  by  a  "  force  "  bolted  to  the  press  slide,  while  the  lower  one 
in  descending  with  the  slide  acts  against  a  stationary  force  fast- 
ened to  the  bed.  It  will  be  understood  that  the  two  body-halves 
of  the  can,  loosely  hooked  together,  are  pushed  over  the  sliding 
horn,  as  shown  in  Fig.  519,  which,  by  means  of  adjustable 
gauges,   secures  accurate  size  and  position.     By  the  use  of  a 


FIG.  519. 


Fig.  520. 


double -horn  machine  the  capacity  of  the  operator  is  nearly 
doubled  as  compared  with  what  can  be  done  on  an  ordinary 
horn  press.  Presses  equipped  with  fixtures  for  double  seaming 
are  used  extensively  for  seaming  5 -gallon  petroleum  cans,  as 
per  Fig.  520. 

Double-seaming  machines  (Fig.  521)  for  seaming  articles  of 
irregular  shape  differ  from  those  of  the  type  shown  in  Fig.  514 
in  that  they  allow  the  seaming  rolls  to  follow  automatically  the 


INTERCHANGEABLE  MANUFACTURING.         445 

shape  of  the  can.     As  they  do  the  seaming  at  the  top  of  the  can, 
they  are  preferable  for  filled  cans.     In  action,  the  pressure  on 


Fig.  521. 


the  foot  treadle,  which  causes  the  pressure  plate  to  clamp  the 
can  and  lid  against  the  chuck,  also  throws  in  the  friction  clutch 
which  starts  the  work.     The  double-seaming  rolls,  controlled  by 


446  '  TOOL-MAKING   AND 

a  cam  made  in  a  piece  with  the  chuck  and  finished  to  the  shape 
of  the  can,  follow  the  shape  of  the  can  automatically,  while  the 
necessary  pressure  to  form  and  finish  the  seam  is  imparted  by 
the  haudles.  These  pressure  handles  in  such  machines  are  so 
arranged  as  to  relieve  the  hand  of  the  operator  from  all  vibra- 
tions due  to  the  irregular  shape  of  the  cans.  Adjustments  for 
different  heights  of  work  can  be  readily  made  by  means  of  a 
hand-wheel,  and  for  different  shapes  by  exchanging  the  can 
chuck,  which  can  be  done  in  a  few  minutes. 

The  rolling  of  seams  on  square  cans  is  usually  accomplished 
in  the  following  manner :  The  can  is  firmly  held  between  two 
disks  made  exactly  to  fit  the  heads  of  the  can;  the  upper  disk 
being  mounted  on  a  vertical  shaft  fastened  rigidly  to  the  upper 
part  of  the  main  frame  of  the  machine  and  the  lower  disk  to  a 
shaft  passing  through  the  lower  part  of  the  frame  and  prevented 
from  turning  by  an  arm  running  in  the  guides,  but  capable  of 
vertical  motion  imparted  to  it  by  a  cam  on  the  treadle  shaft. 

The  steel  rolls  which  operate  on  the  seam  at  the  top  and  bot- 
tom are  carried  by  a  frame  which  rotates  upon  the  upper  and 
lower  stationary  shafts  and  revolves  around  the  can.  These  rolls 
are  mounted  on  levers  pivoted  in  the  rotating  frame,  the  oppo- 
site ends  of  the  levers  being  finished  with  rolls  bearing  against 
star-shaped  stationary  cams  in  two  vertical  shafts  which  gives 
the  "in-and-out  motion"  required  in  passing  around  the  corners 
of  the  cans.  The  rotating  frame  carries  two  sets  of  these  rollers, 
which  press  upon  opposite  sides  of  the  can  at  both  top  and  bot- 
tom, thus  equalizing  the  side  pressure  and  rolling  the  seams  more 
perfectly  than  would  be  possible  by  the  use  of  the  single  set  of 
rolls,  each  seam  being  rolled  twice  in  each  revolution.  There 
are  additional  cams  provided  which,  as  the  machine  comes  to  a 
rest,  move  the  rolls  outward  from  the  surface  of  the  cam,  so  that 
the  latter  may  be  removed  from  the  machine.  Attached  to  the 
bottom  of  the  rotating  frame  is  a  bevel  gear  meshing  with  a  pin- 
ion on  the  pulley-shaft.  The  pulley  is  provided  with  a  friction 
clutch  controlled  by  the  treadle. 

A  cam  being  placed  upon  the  lower  disk,  the  foot  treadle  is 
pressed  and  the  can  is  raised  and  clamped  firmly  between  the" 
upper  and  lower  disks.     The  clutch  is  then  thrown  in,  and  the 


INTERCHANGEABLE  MANUFACTURING.  447 

roller  frame  makes  one  revolution  around  the  can,  the  latter 
remaining  stationary.  After  completing  the  one  revolution  the 
clutch  is  automatically  released,  the  rolls  are  thrown  outward 
and  the  lower  disk  drops,  leaving  the  can  free  to  be  removed. 
The  capacity  of  these  machines  is  from  9,000  to  12,000  cans  in 
ten  hours,  and  the  saving  of  solder  alone  by  the  use  of  each  ma- 
chine amounts  to  from  $15  to  $18  per  day. 

For  double-seaming  the  bottoms  on  large  heavy  work,  such 
as  foot-tubs,  bath-tubs,  wash-boilers,  cauldrons,  and  other  large, 
oval,  oblong,  or  square  articles,  when  the  bottoms  are  required 
to  be  fastened  without  the  usual  recess  next  to  the  double  seam, 
a  large  machine  of  special  design  is  used. 

In  this  machine  a  high  chuck  is  used,  fitting  the  inside  of  the 
article,  and  the  double-seaming  is  done  against  the  inside  of  this 
chuck.  In  order  to  establish  the  correct  position  of  the  bottom 
blank  in  relation  to  the  body,  the  blank  is  usually  stamped  with 
a  slight  depression  at  some  distance  from  the  edge,  which  fits  a 
corresponding  depression  in  the  top  of  the  chuck.  To  facilitate 
the  taking  off  of  high  articles,  there  is  usually  an  upper  arm  on 
the  machine  which  carries  the  clamping-plate  that  is  arranged 
to  swing  out  of  the  way. 

For  the  double-seaming  of  tops,  bottoms,  or  parts  of  special 
shaped  articles,  special  chucks  and  devices  are  necessary ;  how- 
ever, the  principles  involved  are  all  very  much  the  same  in  all 
work  of  this  class,  and  a  knowledge  of  the  methods  in  general 
use  will  enable  anyone  to  accomplish  the  desired  results  without 
trouble. 

CUELING  AOT)    WIEING  PEOCESSES. 

I  will  here  take  up  a  class  of  press  tools  and  fixtures  to  ac- 
complish results  in  sheet  metal  which  a  few  years  back  were  pos- 
sible to  attain  only  by  spinning.  The  operations  in  which  these 
tools  are  used  are  curling  and  wiring  oj)eratlons,  respectively. 
Curling  is  producing  a  curled  edge  around  the  top  of  any  formed 
or  drawn  articles  of  sheet  metal.  Wiring  is  the  curling  of  the 
top  of  such  an  article  around  a  wire  hoop  when  it  requires  stiff- 
ening. The  tools  used  for  either  curling  or  wiring  are  of  almost 
the  same  construction. 


448 


TOOL-MAKING  AND 


J 


Curl  Started 


^A , I "~Al 


Half  Curled 


In  straight  work  and  work  but  slightly  flared  simple  dies  can 
be  used  to  turn  the  metal,  when  wiring,  around  the  wire  and 
under  it,  perfectly  at  one  stroke  of  the  press.  From  2,000  to 
8, 000  pieces  can  be  wired  per  day  of  ten  hours. 

Figs.  523,  527,  530,  and  531  show  cross-sections  of  dies  which 
may  be  used  for  curling  the  edges  of  circular  drawn  shells.  Of 
course,  it  is  impossible  to  see  the  action  of  the  metal  in  work  of 
this  kind  while  the  die  is  working,  but  by  noting  the  condition 

of  the  shells  at  intervals  daring  the 
curling,  by  working  the  die  down  and 
up  by  hand,  the  process  can  be  seen 
and  understood.  The  groove  in  the 
upper  die  (or  lower  die,  as  the  case 
may  require)  must  be  finished  at  the 
back  to  a  perfect  half- circle  of  the 
radius  required,  and  must  be  lapped 
and  polished  until  free  from  all  cuts 
and  scratches,  in  order  to  get  a  clean, 
smooth  curl.  The  sketches  in  Fig. 
522  show  how  the  upper  die  curls  the 
edge  of  a  half-round  shell.  In  the 
first  stage  A  the  metal  has  commenced 
to  curl ;  at  the  next  stage  B  the  metal 
has  curled  to  a  half- circle  of  the  width 
of  the  curling  groove  in  the  upper 
die.  At  C  the  third  stage  .is  shown ; 
the  j)unch  continuing  downward;  as 
the  edge  of  the  shell  passes  the  centre 
of  the  curling  groove  the  pressure  is 
exerted  on  the  top  of  the  half-round 
curled  edge  and  causes  the  metal  to  curl  further  around  until 
the  circle  is  complete,  as  shown  at  D.  In  this  manner  only  one 
operation  is  necessary  to  curl  the  edge  of  a  shell  of  the  type 
shown,  as  the  metal  once  started  around  the  curling  groove  of 
the  upper  die  will  follow  the  curl  on  the  same  radius  as  long 
as  the  pressure  continues,  or  until  the  edge  strikes  the  side  of 
the  shell,  when  it  will  curl  within  the  first  curl.  Thus  a 
shell  may  be  quarter  curled,  half  curled  or  completely  curled 


Fig.  522. 


INTERCHANGEABLE  MANUFACTURING. 


449 


by  the  same  die,  according  to  the  length  of  stroke  to  which  the 
die  is  set. 

When  the  edge  of  a  shell  of  the  shape  shown  at  Fig.  524  is 
desired  to  be  curled  as  shown  at  526  the  work  will  require  two 


Fig.  523. 


dies.     The  first  die  is  to  bend  or  form  the  edges  to  the  upright 
position  and  the  second  die  to  curl  the  edge.     This  second  die  is 


Fig.  524. 


shown  in  Fig.  527.     The  upper  die  is  made  so  as  to  make  the 
entering  of  the  edge  of  the  shell  positive  within  the  curling 


Fig.  526. 


groove,  and  also  so  that  the  straight  inner  wall  will  hold  the  wall 

of  the  shell  while  the  edge  is  curling,  thus  preventing  any  bulg- 
29 


450 


TOOL-MAKING  AND 


iug  during  the  process,  which  would  occur  if  the  inside  of  the 
tool  was  finished  like  the  outside.  In  this  manner  the  metal  is 
held  tightly,  and  as  the  ram  descends  it  must  follow  the  shape  of 
the  curling  groove. 

The  curling  of  the  edges  of  drawn  shells  by  means  of  dies  of 
the  above  type  is  done  in  endless  variety ;  the  articles  worked 


Fig.  527. 


upon  ranging  from  shoe  eyelets  to  bath-tubs,  of  both  round  and 
irregular  shapes.  The  design  and  construction  of  the  tools  de- 
pends en  the  shape,  the  thickness  of  metal,  and  the  diameter  of 


*  TfJT  1M8 


FIG.  528. 

curl  required ;  however,  the  principles  of  construction  involved 
are  the  same  in  all  of  them. 

The  tools  in  Fig.  530  show  how  shells  of  different  shape  may 
be  curled.  For  the  operation  shown  at  A  and  B  a  combination 
die  and  a  bending  die,  respectively,  are  used.  The  curling  as 
shown  at  C  is  done  in  the  die  shown. 


INTERCHANGEABLE  MANUFA CTUBING. 


451 


The  manner  in  which  curling  dies  are  used  for  "wiring"  on 
both  large  and  small  work  will  be  understood  from  Figs.  531 
and  532. 

Dies  of  this  type  may  be  used  for  "wiring"  or  simple  "curl- 
ing" on  round  or  oval  shells,  as  long  as  they  are  straight  or 


Fig.  529  a. 


Fig.  529  b. 


nearly  straight  walled,  and  are  properly  supported  during  the 
process.  A  tool-steel  ring  A  is  attached  to  the  punch-holder. 
The  inner  diameter  of  this  ring  must  fit  accurately  the  inside  of 


<_ _ 


Fig.  530. 


the  shell  to  be  wired,  so  as  to  prevent  bulging  or  crimping  of  the 
walls.     When  "wiring,"  the  ring  B  is  used  in  the  lower  die. 

When  the  dies  are  in  use  a  wire  hoop,  which  fits  the  outer 
diameter  of  the  shell,  is  placed  in  position  on  the  ring  B  and 
around  the  shell  which  is  located  within  the  dies  as  shown.     The 


452 


TOOL-MAKING  AND 


ram  then  descends  and  the  edge  of  the  shell  is  curled  around 
the  hoop,  enclosiug  it  within  it,  as  shown  at  the  bottom  of 
the  cut. 

A  curling  punch  and  die  for  curling  deep  shells  or  articles 
of  thin  sheet  metal,  and  a  section  of  the  press  in  which  it  was 


Fig.  531. 


used,  are  shown  in  Fig.  533.  The  punch  is  located  and  fastened 
within  the  ram,  while  the  die  is  on  a  sliding  table  which  may  be 
pulled  back  and  forth  by  the  operator.     The  horn  or  die  for 


FIG.  533. 


locating  the  work  is  of  slight  taper,  and  consequently  a  solid  one- 
piece  curling  punch  can  be  used,  as  the  decrease  iu  diameter 
when  curling  is  so  slight  that  contraction  of  the  curling  ring  is 
unnecessary.     When  in  use,  the  table  on  which  the  horn  or  die 


INTER  CHANGEABLE  MANTJFA  CT  UBING. 


153 


is  located  is  pulled  out  to  allow  the  article  to  be  slipped  over  it. 
This  is  doue,  aud  the  table  is  moved  back  to  place  against  the 
stop  shown.  The  punch  then  descends  and  the  edge  of  the 
article  is  curled.     The  punch  ascends,  the  table  is  pulled  out,  the 


Fig.  533. 

work  is  removed,  another  piece  is  located,  and  the  operation  is 
repeated.  When  a  press  with  an  automatic  die  slide  is  used  the 
curling  or  wiring  is  done  more  rapidly. 

MANUFACTURING  AEMATUEE  DISKS   AND 

SEGMENTS. 

The  adoption  and  use  of  dies,  power-j^resses,  and  special  sheet- 
metal  working  machinery  for  the  economic  production  of  parts 
of  electrical  apparatus  has  had  great  development  during  the 
past  few  years ;  so  that  to-day  establishments  that  manufacture 
sheet-metal  working  machinery  dispose  of  a  great  portion  of 
their  product  to  electrical  machinery  manufacturing  concerns. 
One  has  only  to  examine  an  electrical  device  or  a  machine  to 
realize  what  a  factor  the  power-press  has  become  in  their  pro- 
duction. The  parts  of  electrical  apparatus  for  the  production 
of  which  such  machinery  is  used  most  extensively,  are  armature 
disks  and  segments  for  motors.  It  is  at  once  obvious  that  the 
requirements  for  such  work  have  led  to  the  designing  of  dies, 
presses,  and  special  machinery  which  differ  in  essential  details 
from  those  used  in  the  general  and  more  familiar  classes  of  sheet- 
metal  working. 


454 


TOOL-MAKING   AND 


An  armature  consists  of  a  wired  " core"  composed  of  thin 
sheet-iron  plates  or  disks  averaging  from  .010  to  .040  thick  and 
10  to  100  inches  in  diameter.  In  many  of  the  best  armatures  the 
disks  are  produced  by  punching  the  centre  hole,  key  slots  and 
notches,  or  winding  slots,  simultaneously  at  one  stroke  of  the 
press.  The  small  sizes  are  thus  produced  in  dies,  while  the 
larger  ones  are  produced  in  sections  or  segments  of  as  large 
size  as  it  is  possible  to  procure  iron  for.  In  the  cheap  and 
inferior  armatures  the  disks  are  first  punched  from  plain  sheets ; 
the  punching  of  the  centre  holes  and  the  key  slots  is  a  second 


FIG.  534. 

operation,  after  which  the  disks  are  assembled  on  shafts,  the 
outside  turned  to  the  required  diameter,  and  the  slots  milled  on 
a  universal  milling- machine. 

Machines  and  dies  used  for  cutting  and  perforating  armature 
disks  and  segments  differ  according  to  the  size  and  shape  and 
number  or  quantity  required.  There  are  in  general  use  four 
methods  for  cutting  armature  disks.  On  the  size  and  quantity 
of  disks  desired  depends  the  practical  value  of  each. 

Disks  of  very  large  diameters,  or  those  required  in  relatively 
small  lots,  are  usually  first  cut  plain  by  shearing  the  outside  cir- 
cle and  afterward  the  inner  circles  on  circular  shearing  machines 
of  the  type  shown  in  Fig.  534.  As  shown,  the  lower  cutter  is  in 
an  angular  position  relatively  to  the  upper,  so  as  to  permit  the 


INTERCHANGEABLE  MANUFACTURING.         455 

making  of  as  clean  a  cut  ou  the  inside  as  on  the  outside.  Disks 
cut  in  this  manner  are  afterward  notched  on  an  automatic  notch- 
ing machine  of  the  type  shown  in  Fig.  535.  A  plain  blanking 
or  notching  punch  and  die  are  located  in  the  press  portion  at  the 
left  and  a  circular  disk  clamped  between  the  two  pads  of  the 
indexing  and  revolving  the  mechanism  at  the  right.  The  index- 
ing is  entirely  automatic,  the  spacing  and  number  of  notches  in 
a  disk  depending  on  the  arrangement  of  the  gearing. 

In  this  machine  the  adjustment  for  different  diameters  is 
made  by  simply  turning  the  hand-wheel  shown.     The  adjust- 


Fig.  535. 

ment  for  different  numbers  of  notches  is  effected  by  means  of 
the  change  gears  shown,  instead  of  a  pawl  and  index-plate  device 
as  is  usually  employed.  Each  set  of  gears  can  be  arranged  to 
answer  for  three  different  numbers  of  notches.  The  index  feed 
is  effected  by  means  of  a  "Geneve  "stop  movement;  but  abso- 
lute correct  indexing  is  assured  by  the  use  of  a  positive  cam- 
actuated  locking  device  for  the  indexing  arbor. 


456 


TOOL-MAKING   AND 


In  connection  with  the  punch  and  die  used  in  a  machine  of 
this  type  a  spring  stripper  is  used,  so  as  to  leave  a  clear  space 
above  the  die ;  making  it  easier  to  introduce  a  new  disk,  and  at 
the  same  time  provide  for  holding  the  disk  under  pressure  when 
the  notch  is  being  punched.  This,  consequently,  obviates  the 
necessity  of  using  a  clamping  plate  over  the  centre  of  the  disk. 


FIG.  537. 

When  disks  of  the  polyphase  motor  type,  having  holes  or 
notches  punched  in  the  inner  periphery,  are  required  to  be 
notched  in  a  machine  of  this  type,  it  is  necessary  to  do  the 
notching  before  the  large  inner  circle  is  removed,  as  its  surface 
is  needed  for  carrying  the  disks  in  notching.  In  such  disks  one 
or  two  small  holes  are  previously  punched  in  that  portion  of 
them  that  is  afterward  cut  away,  in  order  to  serve  as  guides  in 
the  notching  and  centre-hole  punching  operations. 

The  kind  of  disks  which  are  of  moderate  diameter  and  most 
frequently  required  in  large  quantities  are  those  used  for  street- 


FiCx.  538. 


FIG.  539. 


Fig.  540. 


car  motors.  To  produce  them  powerful  power-presses  are  used. 
These  presses  are  equij)ped  with  dies  so  constructed  and  arranged 
that  the  inside  of  the  disk  with  its  key-slot,  and  the  outside  with 
its  notches,  are  cut  simultaneously  at  one  stroke,  as  shown  in 


INTERCHANGEABLE  MANXJFA GTUBING. 


457 


Fig.  540.  This  method  constitutes  the  quickest,  most  accurate, 
and  economical  way  of  manufacturing  armature  disks  in  large 
quantities.  The  presses  in  which  such  dies  as  are  necessary  for 
such  work  are  used,  are  provided  with  knock-out  attachments 
which  discharge  the  scrap  and  the  disks  so  that  they  lie  loosely 
on  top  of  the  dies,  thus  allowing  of  their  easy  removal. 

In  regard  to  the  power-presses  used  for  disk  punching,  it  may 
be  stated  that  the  requirements  of  armatures  for  electric  work 


FIG.  541. 


Fig.  542. 


have  led  to  the  construction  of  presses  which  differ  in  points 
from  those  used  for  other  styles  of  sheet-metal  working.  As  it 
is  always  essential  to  have  the  outside  and  inside  exactly  concen- 
tric, so  that  all  notches  in  the  disks  shall  coincide  perfectly  with 


Fig.  543. 

one  another  when  assembled  in  "  cores, "  it  has  been  found  best  to 
adopt  dies  which,  by  being  cut  simultaneously,  eliminate  the 
inaccuracies  which  are  wellnigh  unavoidable  when  the  cutting 
is  done  in  two  or  more  operations.  In  many  cases,  the  notches 
and  key-seats  are  also  punched  at  the  same  time.  To  accom- 
plish these  results  in  one  operation,  dies  of  great  accuracy  are 


458 


TOOL-MAKING   AND 


required,  which,  in  addition  to  the  cutting  parts,  must  be 
equipped  with  "knock-out"  pads  that  will  automatically  deliver 
the  punched  disks  and  scrap  from  within  the  dies.  The  dies 
used  in  these  methods  of  producing  the  disks  are  known  as 
"compound  dies,"  and  are  usually  built  up  in  sections  which 
have  been  hardened,  ground,  and  lapped  to  size.  However,  not 
infrequently,  they  are  made  in  the  usual  manner,  but  the  results 
are  not  so  accurate.  These  compound  dies  are  very  expensive, 
costing  all  the  way  from  $150  to  $1,000  each.  Fig.  543  shows 
plans  of  a  compound  punch  and  die.  As  a  rule  these  compound 
dies  are  used  in  presses  provided  with  upper  and  lower  die 
knock-outs,  thus  obviating  the  necessity  of  the  strippers  in  the 
dies.  .  The  die  sections  are  located  in  a  steel  casting.  The  rings 
are  of  tool  steel,  carefully  and  accurately  worked  out,  hardened 
and  ground  to  size,  while  the  remaining  ones  are  left  soft.  The 
dark  sections  in  the  figure  indicate  the  cutting  parts. 

As  the  installation  of  the  above-described  method  entails  a 
great  deal  of  expense  and  can  be  adopted  economically  only 
where  disks  are  required  in  large,  steady  quantities,  it  is  at  once 
apparent  that  the  dies  would  be  too  costly  to  use  for  producing 


Fig.  544. 

disks  in  small  lots.  For  this  reason  another  method  is  in  vogue. 
This  method  consists  of  cutting  out  simultaneously  the  plain  out- 
side and  the  hole,  as  shown  in  Fig.  536,  and  then  punching  the 
notches  on  a  notching  press.  By  this  method  a  perfectly  con- 
centric blank  is  produced  ready  to  be  notched.  As  by  this 
method  the  outside  notches  are  cut  separately,  the  power  of  the 


INTERCHANGEABLE  MANTJFA  GT UBING. 


459 


presses  in  which  the  work  is  done  is  equal  to  much  larger- diame- 
ters than  those  used  in  the  method  before  described. 

In  producing  very  large  disks  there  is  a  great  deal  of  scrap, 
but  this  scrap  is  prevented  from  going  to  waste  altogether  by 
being  worked  over  into  disks  of  smaller  size.  From  the  inside 
scrap,  the  projections  corresponding  to  the  key  notches  are  re- 


moved by  forcing  the  disk  through  a  circular  trimming  die  which 
punches  the  centre  hole  at  the  same  time,  and  thus  no  great 
waste  of  stock  is  entailed. 

In  manufacturing  armature  segments  in  very  large  quantities 
the  outside  and  the  holes  are  usually  cut  simultaneously  in  dies 
in  which  the  stripping  of  the  scrap  and  the  segments  from  them 
is  entirely  automatic,  for  both  the  upper  and  lower  sections.  A 
press  specially  designed  and  used  for  this  class  of  work  is  shown, 


Fig.  546. 

equipped  with  proper  tools,  in  Fig.  547.  The  cutting  of  sec- 
tions and  segments  complete  with  dovetails,  and  all  notches  and 
holes  up  to  35f  inches  long,  can  be  done  on  a  press  of  this  sort. 
However,  most  segments  of  large  size  are  first  punched  plain  and 
the  notching  and  perforating  are  done  in  succeeding  operations. 


460 


TOOL-MAKING. 


When  the  plain  segment  blanks  are  not  produced  in  dies,  a 
circular  shear  of  the  same  type  as  that  used  for  disk  cutting  is 
used ;  it  being  equipped  with  a  segment-cutting  attachment,  as 
shown  in  Fig.  545. 

In  Fig.  546  we  have  a  side  view  of  an  armature-segment 
notching  press.  The  segment-notchiug  attachment  on  this  ma- 
chine allows  of  handling  segments  having  a  radius  of  from  36  to 
96  iuches  and  up  to  36  inches  in  length.     The  manner  in  which 


Fig.  547. 


the  segments  are  notched  is  as  follows:  The  segment  to  be 
notched  is  clamped  in  a  holder  at  the  forward  end  of  a  long 
radius  bar,  and  is  traversed  across  the  die  face  by  means  of  an 
indexing  mechanism  and  change  gears  similar  to  those  on  the 
regular  disk  notching  press ;  when  the  segment  is  notched  all 
around  the  outside  or  inner  edge  as  required,  the  press  stops 
automatically.  After  the  operator  releases  a  hand  lever  the  seg- 
ment may  be  returned  to  its  original  position  and  removed  from 
the  press. 


CHAPTER  XXVIII. 

The  Manufacture  of  Accurate  Sheet-Metal  Parts  in 
the  Sub-Press. 

THE   SUB-PEESS. 


The  great  increase  in  the  manufacture  of  innumerable  small 
machines  of  precision  which  are  made  up  almost  entirely  of  sheet - 
metal  parts,  together  with  the  increasing  demand  for  cheap  but 


FIG.  548. 


accurate  watches,  clocks,  time  recorders,  meters,  cyclometers, 
and  other  articles,  the  utility  of  which  depends  entirely  upon 
their  precision,  has  created  a  demand  for  accurate  presses,  dies, 

461 


462  TOOL-MAKING  AND 

feeding  devices,  and  automatic  arrangements  with  which  to  pro- 
duce sheet-metal  parts  in  endless  repetition  with  their  complete 
interchangeability  assured.  For  the  production  of  such  parts, 
dies  of  great  accuracy,  together  with  feeding  devices  which  are 
positive  in  action,  and  the  sub-press  are  necessary. 

Sub-presses  are  distinctly  different  from  the  other  machines 
which  are  used  for  the  usual  or  ordinary  lines  of  sheet-metal 
work,  in  that  they  are  made  so  as  to  form  component  parts  of 
the  dies,  and  that  they  are  used  almost  exclusively  for  the  deli- 
cate dies  which  are  required  in  the  economic  manufacture  of 
parts  of  the  kind  used  in  the  machines,  devices,  etc.,  enumerated 
above. 

UTILITY   OF   THE   SUB-PEESS  NOT   GENEBALLY 
UNDEBSTOOD. 

Notwithstanding  the  extensive  use  to  which  the  sub-press  and 
its  accurately  made  dies  have  been  put,  its  use  and  the  making 
of  the  dies  for  it  are  not  understood  by  superintendents,  fore- 
men, and  tool-makers  of  sheet-metal  goods  establishments  as  they 
should  be.  Thus  the  more  extensive  use  of  these  tools  has  been 
interdicted.  Were  the  case  otherwise,  and  the  utility  of  the  sub- 
press  and  the  making  of  its  dies  more  generally  understood,  there 
would  be  less  worry  and  more  satisfaction  in  the  accomplishment 
of  results  which,  in  many  establishments,  are  at  present  being 
attained  by  means  which  are  now  obsolete.  In  view  of  this  state 
of  affairs  I  feel  that  complete  descriptions  of  the  sub-press,  and 
how  to  use  it  and  its  dies,  will  be  of  great  value  to  all  engaged 
in  the  manufacture  of  accurate  sheet-metal  parts,  articles,  or 
devices. 

PEINGTPAL   USE   OF   THE   SUB-PEESS. 

The  principal  use  to  which  the  sub-press  is  put,  is  for  the 
manufacture  of  sheet-metal  parts  which,  because  of  their  unusual 
accuracy,  have  to  be  produced  in  dies  which  cut  the  outside  and 
the  inside,  as  well  as  any  perforations,  simultaneously,  or  at  least 
within  the  one  compound  die.  By  the  use  of  the  sub-press  and 
its  accurate  dies  the  finest  work  may  be  accomplished  with  ease, 


INTERCHANGEABLE  MANUFACTURING.  463 

as  the  dies  may  always  be  kept  finely  adjusted  for  the  work; 
while  the  enlinement  will  be  perfect,  and  thus  the  possibility  of 
shearing  will  be  entirely  eliminated. 

COST   VS.    LONGEVITY   OF   THE   STIB-PBESS. 

In  regard  to  the  cost  of  a  sub-press  and  a  pair  of  dies  for  pro- 
ducing an  intricate  sheet-metal  part,  the  first  outlay  is  consider- 
able ;  but  then  this  is  really  all  the  cost,  as  the  construction  of 
the  press  is  such  that  no  damage  can  be  done  to  it  while  it  is 
being  set  up  or  run  in  the  power-press ;  while  the  dies  for  it 
require  but  little  repairs  outside  of  an  occasional  grinding  of  the 
faces.  When  it  is  stated  that  from  50,000  to  100,000  perfectly 
interchangeable  blanks  may  be  cut  and  pierced  in  a  sub-press 
without  grinding  the  punch  and  die  faces,  the  accuracy  and  long- 
evity of  the  tools  may  be  imagined. 

HOW  TO   CONSTBTTCT   A   SUB-PBESS. 

In  order  to  be  able  to  construct  a  sub -press  or  a  set  of  dies 
for  it  the  tool-maker  must  be  both  skilled  and  accurate,  and  must 
use  great  judgment ;  possessing  these  qualities  he  may,  by  care- 
fully digesting  the  following  described  methods,  be  sure  of  suc- 
cess. 

Fig.  548  shows  in  vertical  section  and  Fig.  549  in  plan,  a 
sub -press  such  as  is  used  in  all  watch,  meter,  and  cyclometer 
factories.  The  sub-press  consists  of  the  stand  1,  the  plunger  2, 
the  base  3,  the  nut  4,  to  tighten  the  babbit  lining,  and  the  hook 
nut  5,  which  connects  the  j>ower-press  plunger  with  the  plunger 
2  of  the  sub-press.  The  stand  1  is  the  first  part  machined.  It 
is  faced  and  bored  on  the  bottom,  and  then  the  barrel  is  faced 
and  recessed  to  suit  a  flange  by  means  of  which  the  plunger  2  is 
centred  at  one  end  for  babbitting.  The  stand  is  then  ready  to 
be  drilled  and  tapped  for  the  fillister  head-screws,  by  means  of 
which  it  is  fastened  to  the  base.  These  screws  are  also  used 
to  fasten  the  stand  to  a  special  lathe-chuck,  by  means  of  which 
it  is  bored  3  degrees,  taper-faced  on  the  other  end,  and  then 
turned  for  the  adjusting  nut,  but  not  threaded  until  the  stand 
has  been  babbitted.     The  stand  having  been  bored  it  is  then  set 


464 


TOOL-MAKING  AND 


up  in  the  shaper  or  keysetter,  and  four  grooves  are  planed  in  the 
inside,  parallel  with  the  taper,  to  prevent  the  babbitt  lining  from 
turning. 

We  now  rough-turn  the  plunger  2,  back-rest  it,  and  then  bore 
it  for  the  punch  piston ;  after  which  it  can  be  threaded  for  the 

nut  5.  This  nut  should  be  made 
of  machinery  steel,  and  have  two 
flats  milled  on  it  at  o  o,  so  as  to 
be  able  to  remove  it  from  the 
plunger.  With  this  nut  well 
screwed  down  the  plunger  should 
be  turned  to  within  about  .005 
inch  of  the  finish  size,  and  then 
finished  by  grinding,  making  sure 
to  have  it  perfectly  parallel; 
after  which  it  should  be  placed  in 
the  miller  vice,  and  four  grooves 
milled  in  it,  being  sure  to  have 
the  miller  vice  exactly  in  line ;  if 
the  vice  is  slightly  "out"  a  twist- 
ing motion  will  occur  in  the 
plunger  when  in  operation  in  the 
press,  and  this  will,  of  course, 
spoil  the  dies.  ]STow  we  draw-file 
the  plunger,  using  No.  2  emery 
stick,  which  will  give  better  re- 
sults than  a  file,  and  then  all  is 
ready  for  the  babbitting.  We 
get  the  babbit  at  the  right  heat, 
pour  it,  and  allow  it  to  rise 
about  £  inch  above  the  top  of  the 
stand. 

As  soon  as  the  stand  has  cooled  enough  to  handle,  the  plun- 
ger should  be  forced  down  far  enough  to  allow  the  babbitt  to  be 
faced  and  squared  off  on  the  end,  and  the  thread  cut  on  the  end 
of  the  stand  or  nut  4.  ISTow  remove  the  plunger  from  the  stand, 
and  locate  the  stand  in  the  lathe  again;  then  cut  a  spiral  oil 
groove  of  about  1-inch  pitch  in  the  babbitt  lining.     The  stand 


Fig.  549. 


INTERCHANGEABLE  MANUFA CTUBING. 


465 


and  plunger  should  now  be  secured  in  the  power-press,  and 
pumped,  using  plenty  of  oil,  and  tightening  down  the  nut  occa- 
sionally so  as  to  get  a  good  bearing.  It  must  be  watched  at  this 
stage,  in  order  that  excessive  friction  may  -not  heat  the  babbitt 
lining  sufficient  to  cause  it  to  swell,  and  thus  destroy  the  stand. 
Now  reface  the  stand  in  the  lathe,  and  face  the  bottom  and  bore 
the  seat  about  2  degrees  taper  to  fit  over  the  taper  boss  on  the 


Fig.  550. 

base.  The  plunger  may  now  be  removed  from  the  stand,  back- 
rested,  and  recessed  for  the  dies.  The  base  can  then  be  located 
on  the  face-plate  of  a  lathe — having  previously  planed  the  bot- 
tom— and  the  boss  turned  3  degrees  taper  to  suit  the  stand ;  also 
recess  it  for  the  dies  and  lower  stripper,  after  which  it  can  be 
drilled  and  counter-bored,  and  then  doweled  to  secure  the  per- 
fect alignment  of  the  two  sections. 


SETTING  AND   WORKING   A   SUB-PRESS. 

The  sub-press  can  be  worked  in  almost  any  power-press  of 
suitable  space.  However,  usually,  a  special  press  is  used  for  the 
purpose,  as  a  short  stroke  and  a  stiff  arch -framed  press  best  meet 
the  requirements ;  Fig.  549  shows  a  press  of  this  kind. 

To  set  a  sub -press,  simply  slip  it  into  place,  as  shown  in  Fig. 

549,  by  sliding  the  steel  neck  of  the  plunger  into  the  press-slide 

hook,  and  theu  locate  the  hold -drawn  clamps  into  their  places 

and  tighten  the  screws  or  nuts,   thus  fastening  the  sub -press 

firmly  to  the  bed  of  the  power-press  or  bolster  plate.     The  dies 
30 


466  TOOL-MAKING  AND 

may  now  be  set  and  all  is  ready  to  proceed  with  the  punching. 
The  changing  of  a  sub-press  is  very  quickly  done,  as  no  special 
skill  is  required.  There  are  several  different  styles  of  sub-press 
frames ;  the  most  common  is  the  round  barred-arch  shape.  An 
overhang  pattern  is  often  used.  For  the  very  largest  work, 
such  as  clock  or  time-register  frame  backs,  a  four-pillar  sab- 
press,  which  cuts  quite  large  blanks  from  stock  as  thick  as 
T3-g  inch,  is  used.  The  manner  in  which  the  punching  in  a  sub- 
press  is  done  must  not  be  confounded  with  ordinary  punching, 
as  it  is  done  in  a  different  manner.  As  a  rule  three  or  more 
operations  are  performed  at  one  stroke  of  the  press — that  is,  cut- 
ting the  outside,  cutting  the  centre,  perforating  the  blank,  and 
lettering  it  all  at  once.  The  stock  to  be  punched  is  securely 
held  between  the  stripper  plates  and  pads ;  thus  the  die  is  com- 
pound; thus  the  metal  is  straightened  and  held*  perfectly  flat 
while  being  worked  upon,  and  each  and  every  piece  produced  is 
an  exact  counterpart  of  the  one  previously  cut. 

ACTION   OF   THE   DIES— FEEDING    OF    THE  METAL. 

In  the  production  of  the  most  accurate  classes  of  work  in  the 
sub-press,  the  punch  does  not  enter  the  die  proper,  but  descends 
within  a  shade  of  its  face,  thus  parting  the  blank  from  the  stock, 
and  no  more ;  the  strippers  flatten  its  edges  out  square.  It  must 
be  understood,  though,  that  the  die  and  punch  faces  must  be 
perfectly  flat  and  without  any  shear  in  order  for  the  work  to  be 
produced  accurately ;  for  this  reason  a  stiff,  well-made  press  is 
required.  Because  of  constructing  the  dies  in  this  manner  their 
longevity  is  greatly  extended,  as  the  punches  merely  pass  through 
the  comparatively  soft  stock  and  not  in  and  out  of  the  hardened 
dies,  which  would  shear  and  wear  them  quite  rapidly.  Never, 
under  any  circumstances,  allow  the  punches  to  enter  the  dies,  as 
this  will  spoil  the  tools  in  a  short  time. 

As  the  sub-press  is  a  small,  convenient  machine  in  itself, 
with  its  dies  and  punches  always  in  perfect  alignment,  with  no 
possibility  of  fitting  out  of  order,  it  is  always  set  ready  for  work 
aud  all  chances  of  bad  or  inaccurate  work  are  eliminated.  While 
the  first  cost  of  this  little  machine  is  large,  in  the  long  run  it  is 


INTERCHANGEABLE  MANUFACTURING.         467 

the  cheapest  die  that  can  be  devised  for  the  accurate  and  rapid 
production  of  perfectly  interchangeable  sheet-metal  parts.  It  is 
this  little  tool  that  has  made  possible  the  manufacture  of  the 
"dollar  watch." 

Eoll  feeds,  or  other  automatic  feeding  appliances,  are  often 
added  to  the  presses  in  which  these  sub-press  tools  are  used.  As 
the  articles  cut  are  forced  back  into  their  place  in  the  stock  from 
which  they  were  punched  by  the  strippers  in  the  dies,  the  meta- 
stock  is  kept  straight  and  it  is  punched  and  accurately  fed  along 
under  the  dies  at  a  very  high  speed,  from  75  to  130  punchings 
per  minute  being  produced. 


CHAPTER  XXIX. 

Engraving,    Sinking,    Constructing,   and  Using  Dies 
for  Medals,  Jewelry,  Coins,  and  Art  Goods. 

WORKMAN  VS.    ARTIST. 

The  cutting  and  engraving  of  steel  dies  for  the  embossing  of 
medals,  jewelry,  and  fine  sheet-metal  work  is  an  art  by  itself — an 
art  which,  besides  requiring  mechanical  skill  and  a  knowledge 
of  the  use  of  metal-working  tools,  requires  a  natural  talent  for 
that  kind  of  work  and  the  possession  of  that  artistic  ability  that 
comes  from  the  love  of  things  beautiful.  Without  that  ability 
the  die-sinker  is  merely  a  workman,  and  will  be  incapable  of 
originality :  it  is  the  talent  that  makes  the  artist.  However,  to 
those  who  are  already  skilled  in  the  art  of  die-making  and  who 
possess  to  a  certain  extent  the  ability  to  duplicate  designs,  this 
chapter  will  prove  greatly  instructive ;  while  to  those  less  gen- 
erously endowed  the  information  contained  herein  will  help  them 
to  progress  further. 

ENGRAVING   A   HOB    FOR    SINKING    A    MEDAL    DIE. 

In  making  the  dies  for  medals,  etc.,  the  most  approved  prac- 
tice is  as  follows :  Taking  a  blank  ready  to  be  cut,  Fig.  551,  we 
grind  the  face  dead  smooth  and  then  either  copper  it  with  a  solu- 
tion of  sulphate  of  copper  or  give  it  a  thin  coat  of  zinc  white 
and  allow  it  to  dry.  We  sketch  the  medallion  portion  on  this 
surface,  as  in  Fig.  552,  and  cut  away  to  the  necessary  depth  all 
the  outer  sections  until  a  perfect  silhouette  of  the  figure  is  ex- 
posed, as  in  Fig.  553.  After  this  the  coarser  details  are  cut  in, 
using  small  chisels,  riffles,  and  gravers,  and  boldly  rounding  all 
portions  which  are  to  appear  thus,  as  shown  in  Fig.  554.  The 
last  and  most  particular  part  of  the  work  is  to  eugrave  and  chase 
in  the  fine  artistic  details  until  the  work  appears  finished,  as  in 

468 


INTERCHANGEABLE  MANUFACTURING.         469 

Fig.  555.     The  "hob"  for  sinking  the  die  for  the  face  of  the 
medal  is  thus  made. 


MAKING  DIES   FOR  EMBOSSING   JEWELRY. 

In  the  making  of  dies  for  the  embossing  of  jewelry  the  usual 
practice  consists  of  working  out  the  sample  first  to  the  shape  re- 
quired, after  which  it  should  be  soldered  to  the  end  of  the  piece 
of  steel  which  is  to  form  the  punch.  These  pieces  of  steel  are 
usually  kept  on  hand  and  are  turned  to  1£  inches  diameter  and 


Fig.  551. 


Fig.  552. 


Fig.  553. 


Fig.  554. 


Fig.  555. 


are  about  5  inches  long,  with  the  small  end  bevelled  to  a  size  just 
large  enough  to  cover  the  sample.  After  the  sample  has  been 
soldered  to  the  end  of  the  punch  blank  the  outline  of  the  templet 
is  carefully  and  accurately  worked  out  on  the  end  of  the  punch 
by  the  best  means  available ;  the  bench  miller  will  prove  the  best 
means  to  adopt  for  doing  this  part  of  the  work.  Carry  out  the 
outline  to  a  distance  of  about  -g3¥  inch  from  the  face  of  the 
punch ;  then  take  the  punch  to  the  shaper  and  carry  the  shape  up 
the  length  of  the  punch ;  tapering  it  to  run  out  about  1^  inches 
from  the  face.  After  this  carefully  file  and  finish  all  points 
round,  so  that  the  end  of  the  punch  will  have  the  perfect  outline 
of  the  sample.  The  sample  may  now  be  removed  and  the  face 
of  the  punch  shaped  as  the  finished  article  is  to  appear. 

This  shaping  requires  a  little  exercise  of  the  artist's  talent, 
but  it  is  not  very  difficult  if  gone  at  with  a  little  thought  and 
system.  The  systematic  method  would  be  to  coat  the  end  of  the 
punch  with   copperas  solution,    and   scribe  a  line   completely 


470  TOOT^MAKING  AND 

around  the  punch  a  distance  from  the  end  face  equal  to  the  thick- 
ness of  the  finished  article. 

The  dies  are  usually  made'  of  round  annealed  stock,  turned 
to  1-J  inches  diameter,  the  ends  faced  to  about  -g-  inch  thick,  and 
the  face  into  which  the  impression  is  to  be  struck  finished  to 
a  very  high  polish.  ]STot  the  slightest  scratch  is  permissible 
upon  the  face  of  either  punch  or  die.  This  being  done,  take  the 
punch — which  we  will  now  call  "master"  punch — and  the  die 
blank,  to  either  a  screw-press  or  drop-press,  set  both  in  their 
respective  places,  and  when  all  is  in  readiness,  carefully  clean 
both  and  oil  very  slightly  with  oily  fingers.  All  being  firmly 
fixed  in  position,  the  impression  is  now  made.  If  a  screw-press 
is  used  a  few  strong  blows  will  be  necessary,  and  if  a  drop -press 
estimate  about  the  proper  height  from  which  to  drop  the  weight 
with  the  surface  to  annealed  piece,  which  will  soon  teach  one 
about  how  much  is  necessary  to  strike  a  given  depth.  Raise  the 
weight  and  let  fall,  catching  the  weight  before  a  second  blow  can 
be  struck.  The  result  of  this  will  be  a  clean-cut  impression,  with 
the  original  polish  of  surface  almost  perfectly  preserved  but  car- 
ried down  into  the  blank.  Of  course  the  metal  will  be  thrown 
up  around  the  impression,  and  this  can  be  faced  off  in  either  a 
lathe  or  a  shaper,  since  it  is  necessary  to  strike  a  little  deeper 
than  required  because  of  the  edges  being  rounded.  The  die  is 
now  marked,  etc. ,  and  hardened,  using  something  to  insure  its 
coming  out  of  this  process  clean,  and  then  the  impression  is  pol- 
ished out.  It  is  very  necessary  for  work  of  this  kind  that  the 
dies,  etc.,  be  highly  polished,  and  especially  so  when  working 
gold-filled  stock,  for  the  smoother  the  work  comes  from  these 
dies,  the  less  buffing  will  be  necessary  to  bring  it  to  a  finish. 

For  the  high  finish,  either  Vienna  lime  or  fulminate  of  iron 
will  give  excellent  results.  Chuck  a  round  stick — orange  wood 
— in  a  speed-lathe  or  drill-press.  Shape  the  end  with  a  file 
while  running,  and  use  either  of  these  preiDarations  with  water. 
The  Vienna  lime  is  cleaner,  fulminate  of  iron  gives  the  most  sat- 
isfactory results.  We  now  have  a  die  ready  for  business,  and 
when  this  becomes  worn  large  from  use,  which  it  surely  will  do 
in  time,  another  die  can  be  struck  from  our  master  punch. 

After  a  punch  has  been  found  to  give  the  results  sought  for, 


INTERCHANGEABLE  MAN  UFA  C  TUBING.         471 

it  is  a  very  good  plan  to  strike  off  several  dies  at  one  time, 
especially  if  manufacturing  anything  like  this  in  large  quanti- 
ties, as  there  is  a  gritty  surface  to  annealed  pieces  which  will 
soon  wear  ont  a  die,  and  the  form  of  the  piece  being  changed, 
will,  in  a  greater  or  lesser  degree,  affect  subsequent  operations. 
It  is  a  good  plan  also  to  strike  off  one  die  deeper  than  is  in  regu- 
lar use,  finish,  and  reserve  as  a  master  die.  This  would  then 
make  it  possible  to  reproduce  the  punch  also  if  by  accident  or 
otherwise  it  became  damaged  or  lost. 

To  produce  a  punch  from  the  master  die  we  must,  of  course, 
use  an  annealed  blank  turned  up  as  before  and  shaped  to  the 
impression  in  the  die.  This  can  well  be  done  by  laying  out  the 
outlines  on  the  end  of  the  punch  blank,  shape  it  accordingly  in 
the  bench  miller,  and  file  it  to  about  the  desired  shape.  Place 
the  master  die  and  punch  blank  into  the  die,  though  not  hard. 
Now  remove  the  punch  and  ease  off  all  spots  showing  contact. 
Eeplace  punch  blank  and  repeat  until  nearly  the  exact  form  has 
been  taken,  then  ease  off  the  sides  slightly,  polish  highly,  and 
return  to  the  press  for  a  finishing  blow.  The  object  of  this  is  to 
work  the  punch  nearly  to  shape,  and  to  fit  the  die  so  that  in  the 
finishing  blow  the  first  contact  will  be  in  the  bottom  of  the  im- 
pression. The  metal  seems  to  flow  into  the  die  better  where  con- 
tact is  at  first,  and  should  there  be  a  scratch  or  other  sharp 
indentation,  it  cannot  be  rounded  out.  It  is  also  interesting  to 
note  that  if  a  drop  of  oil  gets  pocketed  in  the  bottom,  this  oil 
will  prevent  the  die  being  filled  out,  no  matter  what  pressure  is 
exerted,  so  that  the  rule  seems  to  be  for  either  the  punch  or  the 
die:  "Let  there  be  no  scratches  or  dents  in  either  surface;  polish 
highly ;  keep  the  surfaces  clean  from  grit,  etc. ,  and  oiled  but 
slightly  with  slightly  oiled  fingers,  and  rubbed  on  at  that." 
Finish  the  taper  part  of  the  punch  in  the  shaper  and  vice,  as 
already  explained.     Polish,  harden,  and  finish  as  usual. 

Quite  contrary  to  what  might  be  expected  by  many,  sinking 
small  dies  in  this  manner  does  not  induce  strains  sufficient  to  be 
of  any  serious  consequence,  and  I  dare  say  that  with  annealed 
steel  there  is  no  more  chance  of  loss  than  by  the  method  of  first 
heating  before  striking  the  impression.  In  fact,  an  experienced 
man  almost  never  loses  a  die. 


472  TOOL-MAKING   AND 

When  not  in  use  the  master  punch  and  master  die  should  be 
coated  with  vaseline  and  stored  away  in  a  vault  or  other  safe 
place.  If  preferred,  these  tools  can  be  packed  in  powdered  lime, 
same  as  polished  spring  wire  is  packed,  to  preserve  the  polish. 

CHASING    THIMBLE,    CANE,    WHIP,    AND    TJMBEELLA 

MOUNTINGS. 

The  small  indentations  on  the  end  of  a  thimble,  cane,  whip, 
and  umbrella  mountings,  are  embossed  with  knuel  wheels  where 
the  design  will  permit.  Very  fine  work  is  hand-chased,  which 
is  performed  by  filling  the  articles  with  lead  and  afterward  driv- 
ing the  thin  metal  into  the  lead  with  chasing  tools,  the  latter 
being  a  small,  blunt  chisel  of  proper  shape  to  fit  the  designs  or 
ornaments  wanted. 

MODELING   INTRICATE    DIE  PATTERNS. 

The  modeling  of  intricate  die  patterns  is  accomplished  in 
different  ways,  according  to  the  nature  of  the  work :  carving  in 
wood,  moulding  in  plaster,  moulding  from  "modeller's  wax," 
or  moulding  in  gelatin.  The  once  most  common  method,  but 
now  wellnigh  obsolete,  was  that  of  carving  in  wood.  For  large, 
bold  designs  the  plaster  cast  is  the  best.  First  a  rough  outline 
of  the  work  is  formed  from  freshly  mixed  plaster.  After  this 
has  set  it  is  cut  or  carved  into  the  desired  form  by  keeping  it 
moist  and  using  sharp  wooden  or  brass  tools ;  steel  tools  will  not 
do,  as  they  rust  rapidly.  In  some  cases  modellers  make  their 
first  model  of  clay,  then  make  a  plaster  or  gelatin  mould  from 
this  by  casting ;  and  lastly  a  reproduction  of  the  original  model 
from  this  cast. 

GELATIN  MOULDS. 

When  a  clay  model  has  been  made  and  it  is  designed  to  repro- 
duce in  gelatin,  soak  the  best  white  glue  in  cold  water  for 
twenty -four  hours,  drain  off  all  the  water,  and  melt  the  soaked 
glue  in  a  water- jacketed  kettle,  bringing  it  to  the  thickness  which 
will  give  it  the  consistency  of  soft-rubber  when  cold.  To  pre- 
vent the  gelatin  from  sticking,  moisten  the  model  with  a  mixt- 


INTERCHANGEABLE  MANUFACTURING.         473 

ure  of  common  soap  and  lard  oil.  Pour  the  glue  upon  the 
model,  the  latter  being  incased  in  a  lead  or  board  box ;  allow  the 
mould  to  cool  for  about  twelve  hours,  and  then  separate  the  cast 
from  the  model  by  gently  rapping  around  the  edges  of  it.  If 
the  model  has  two  surfaces  from  which  casts  are  to  be  made,  a 
thread  should  be  attached  to  the  back  and  extended  out  of  the 
mould  at  both  ends,  so  that  it  may  be  used  for  cutting  open  the 
mould  and  removing  the  model  after  the  mould  has  cooled. 

Another  good  recipe  for  a  gelatin  mould  is  the  following : 
Dissolve  20  parts  of  fine  gelatin  in  100  parts  of  hot  water,  and 
add  one-half  part  of  tannin  and  the  same  amount  of  rock  candy. 
A  mould  made  of  glue  or  gelatin  only  will  become  more  durable 
if  a  solution  of  bichromate  of  potash  and  water  is  poured  over  it 
and  the  mould  afterward  exposed  to  the  sun.  Use  one  part  of 
bichromate  to  ten  parts  of  water.  Always  remember  to  oil  all 
models  before  covering  them  with  glue  or  gelatin,  otherwise  you 
will  fail  to  secure  a  good  mould  and  may  warp  the  model. 

-     USE   OF   "MODELLEB'S  WAX." 

To  make  impressions  of  dies  in  which  the  designs  are  very 
elaborate,  or  composed  of  very  fine  lines  and  curves,  use  "mod- 
eller's wax."  To  make  this  wax,  take  two  parts  of  beeswax  to 
one  part  of  bayberry  wax ;  dissolve  and  mix  well  and  then  spread 
it  over  the  face  of  the  die  while  warm,  first  moistening  the  face 
of  the  die  with  strong  soap  water  to  prevent  sticking.  To  secure 
an  impression  of  a  large,  bold  design,  use  "dentist's  plaster," 
mixing  it  with  water  until  about  as  thick  as  molasses.  It  will 
be  necessary  to  work  fast,  as  the  plaster  will  set  quickly.  Wipe 
the  face  of  the  die  with  lard  oil  and  common  soap  solution  and 
then  spread  the  plaster  over  the  die,  running  it  from  end  to  end. 
After  the  plaster  has  set,  heat  the  die  slightly  and  lay  it  aside 
for  about  twenty  minutes,  after  which  rap  the  edges  of  the  die 
until  the  impression  separates  from  it.  In  pouring  the  plaster, 
allowing  it  to  flow  from  side  to  side  will  prevent  the  formation 
of  air  bubbles  in  the  depressions.  The  further  exclusion  of  air 
may  be  ensured  by  paddling  or  churning  the  plaster.  As  plaster 
shrinks  considerably  in  drying,  it  will  be  necessary  to  remove  the 
cast  from  the  model  as  soon  as  it  becomes  dry. 


474 


TOOL-MAKING   AND 


As  a  rule,  no  matter  how  carefully  plaster  casting  is  done, 
some  defects  will  appear  in  the  casts,  which  will  have  to  be 
patched.  Wait  until  they  are  thoroughly  dry  and  cold  and  then 
scrape  the  damaged  surfaces  before  patching. 

DIES   FOR   FORMING   LARGE   ORNAMENTAL 
ARTICLES. 

The  dies  used  for  bending  and  forming  large  ornamental  arti- 
cles of  sheet  metal  are  usually  cast  iron.  Very  little  work  is 
done  on  such  dies,  as  they  are  cast  from  a  carefully  prepared 
model,  a  facsimile  of  the  article  to  be  formed,  using  it  as  a  pat- 
tern and  working  out  the  die  surfaces  in  a  manner  similar  to  the 
moulding  of  a  pattern  in  sand.  Drop  dies  are  often  made  in 
this  way,  and  from  these  steel  dies  are  dropped,  producing  them 
to  almost  the  correct  finished  shape,  thus  dispensing  with  con- 
siderable difficult  filing,  chipping,  and  graving. 

WATER,    OR  FLUID   DIES. 

All  kinds  of  hollow  ware,  such  as  lamp  bodies,  artistic  toilet 
cases,  match  safes  such  as  shown  in  Fig.  556,  silver  and  Britan- 
nia ware  and  ornamental  soft  brass  shapes,   are  produced  in 


Fig.  556. 

almost  exact  reproductions  of  chased  work  by  means  of  the 
"water  die,"  of  the  type  shown  in  Fig.  557.  The  "die"  con- 
sists of  a  hinged  mould  having  the  desired  decorations  cut  on  the 
inside.  These  moulds  are  usually  cast  from  carefully  carved 
models  and  are  then  finished  and  touched  up  until  all  fine  details 


INTERCHANGEABLE  MANUFA  CT UBING. 


475 


are  sharp  and  distinct.  A  special  close-grained  cast  iron  is  nec- 
essary for  such  moulds.  In  use,  the  mould  or  "die"  is  placed 
under  the  press  and  the  shell  to  be  swelled  and  decorated  is  filled 
with  water  and  enclosed  within  it.  A  plunger  fitted  to  the  ram 
of  the  press,  and  fitting  the  opening  in  the  top  of  the  mould 
tightly,  descends  and  causes  the  confined  fluid  to  swell  out  the 
metal  into  the  designs  in  the  mould.     This  is  a  very  economic 


Plunger 

Knurled  Sleeve 


FIG.  557. 

way  of  producing  decorated  hollow  ware,  and  is  used  almost  to 
the  exclusion  of  all  other  methods  in  the  large  silverware  estab- 
lishments. To  produce  very  plain  figures,  swells  and  shapes  in 
soft  metals,  a  piece  of  soft-rubber  is  used  as  a  swelling  agent, 
the  plunger  compressing  it  on  the  descent. 


COMBINATION   DIES   FOR  EMBOSSED   WORK. 

Flat,  stamped,  embossed,  or  raised  sheet-metal  articles  are 
usually  drawn  and  stamped  up  in  a  first  operation  and  trimmed 
afterward  in  a  plain  trimming-die.  Sometimes,  when  the  de- 
signs are  simple  or  shallow,  the  articles  are  i^roduced  in  one 
operation  in  a  combination  drawing  and  embossing  die.  This  is 
not  done  as  a  rule,  as  the  metal  is  apt  to  draw  and  form  un- 
equally, and  thus  the  finding  of  a  blank  which  will  draw  up  per- 
fectly without  fins  or  rough  edges  is  very  difficult.  Again,  the 
two  operations  are  combined  in  a  progressive  die,  in  which  the 
metal  is  first  stamped  and  drawn,  or  vice  versa,  and  then  fed 
along;  and  trimmed  or  blanked  out. 


476  TOOL-MAKING   AND 

MAKING  "HOBS"  AND   SINKING   EMBOSSING  DIES. 

In  the  making  of  embossing  dies  several  methods  are  in 
vogue.  Sometimes  both  dies  are  made  of  steel,  or  one  of  steel 
and  one  of  copper  or  brass,  or  one  of  hard  bronze  and  one  of 
soft  brass,  while  for  very  large  work  of  bold  designs  one  die  is 
made  of  cast  iron  and  the  other  of  brass. 

In  making  steel  dies  for  striking  up  gold,  silver,  and  other 
valuable  metals  the  first  operation  consists  in  carefully  anneal- 
ing the  blank  which  is  to  form  the  master  die  or  "hob,"  and  then 
getting  a  dead  smooth  finish  on  the  face,  which  is  then  cut  and 
engraved  and  cut  until  an  exact  reproduction  of  the  required  de- 
sign is  raised  on  it.  Careful  engraving  and  scraping  and  giving 
the  proper  amount  of  draft  and  radius  to  certain  points  will  be 
necessary  in  order  to  obviate  the  tendency  of  the  metal  to  cut 
apart  while  being  worked;  this  will  be  most  likely  to  occur 
where  perpendicular  lines  or  surfaces  are  presented.  After  hav- 
ing finished  and  polished  all  portions  of  the  design  the  "'hob" 
may  be  hardened  and  drawn  to  a  deep  straw  temper.  We  now 
have  a  master  die  or  "hob"  with  which  to  sink  the  other  die. 
This  "hob  "  is  fitted  to  the  ram  of  the  press  or  of  the  drop  ham- 
mer, whichever  it  is  to  be  used  in. 

We  now  secure  another  annealed  blank,  and  carefully  finish 
the  top  and  bottom.  The  master  die  is  secured  in  the  press  ram 
and  the  blank  is  placed  directly  under  it.  Both  faces  of  the  dies 
are  oiled  and  the  master  die  is  forced  into  the  soft  face  of  the 
blank  until  a  perfect  impression  of  every  detail  and  line  in  the 
master  die  appears.  This  will  require  much  time  and  patience, 
it  being  necessary  to  remove  the  blank  several  times  and  cut 
away  the  surplus  metal  thrown  up.  After  the  necessary  amount 
of  clearance  has  been  given  the  sunken  die,  and  all  points  are 
polished,  it  can  be  trimmed,  faced  and  hardened,  and  tempered. 
From  this  die  a  brass,  bronze,  or  copper  "force"  is  then  struck 
up,  which  is  used  in  place  of  the  master  die  in  the  production  of 
the  articles  desired.  If  many  dies  of  the  same  kind  are  to  be 
made,  such  as  for  coins,  a  number  of  sets  are  sunk  from  the  mas- 
ter die,  which  is  kept  for  that  purpose  alone;  thus  the  exact 
duplication  of  the  design  is  assured  in  all  the  dies.     For  coins, 


INTERCHANGEABLE  MANUFACTURING.  477 

of  course,  both  dies  are  of  steel.  In  coin  dies  the  date,  which 
changes  from  year  to  year,  is  stamped  in  by  hand  after  the  im- 
pression of  the  master  die  or  "hob"  has  been  struck. 

In  using  a  master  die  for  making  impressions  the  surfaces  of 
the  "hob  "  and  the  blank  should  be  kept  well  oiled  and  the  press 
should  be  turned  very  slowly  by  hand.  By  keeping  the  master 
die  for  making  impressions  only,  exact  duplicates  of  the  worn- 
out  dies  may  be  produced,  this  being  not  possible  by  any  other 
method,  as  no  engraver  can  exactly  duplicate  his  work  by  hand. 

When  making  very  large  steel  dies  by  the  method  described 
above  it  will  be  found  necessary  to  drop  the  blank  hot.  Heat 
the  blank  to  a  cherry  red,  drop  the  master  die,  remove  the  blank, 
remove  the  scale,  trim  and  work  out  the  surplus  stock,  and  then 
re-drop  cold.  A  perfect  impression  will  be  produced  in  this 
manner. 

BEONZE,  BBASS,  AND   COEEEE  DIES. 

The  making  of  bronze,  brass,  or  copper  dies  for  embossing 
thin,  soft  sheet  metal  in  shallow  designs  and  shapes  is  usually 
accomplished  by  first  casting  from  wooden  or  modelled  patterns, 
and  then  taking  a  plaster  cast  of  this,  from  which  a  mould  or 
matrix  is  secured  which  is  carefully  scraped  and  polished.  This 
matrix  should  be  of  hard  brass  or  bronze,  and  the  mould  of  much 
softer  metal,  so  that  it  may  be  forced  or  dropped  into  it  until  a 
perfect  impression  appears.  It  will  be  found  in  dies  of  this  kind 
that  the  surfaces  will  wear  surprisingly  long,  as  they  become 
hard  and  tough  through  the  dropping  x>rocess. 

It  must  always  be  remembered  that  in  all  kinds  of  engraved 
dies  a  feature  of  great  importance  in  their  making  is  the  neces- 
sity of  cutting  deeper  all  depressions  and  fissures,  so  as  to  leave 
all  the  higher  portions  in  a  position  to  be  perfectly  smooth  and 
polished.  This  is  to  prevent  the  marring  or  splitting  of  the  em- 
bossed side  of  the  article. 

For  the  production  of  ornamental  tinware  and  other  articles 
in  which  the  ornamentation  is  coarse  and  bold,  cast-iron  dies  and 
brass  or  hard  babbitt  moulds  are  used.  These  dies  require  little 
labor  or  skill  to  produce,  as  the  plaster  casts  or  moulds  for  the 
dies  can  be  relieved  in  all  deep  places,  and  thus  it  is  not  neces- 
sary to  rout  out  the  brass  mould  afterward. 


478  TOOL-MAKING. 

When  the  article  required  to  be  embossed  is  very  deep,  or 
where  the  designs  and  ornamentation  are  much  raised,  it  will  be 
necessary  to  accomplish  the  embossing  with  two  sets  of  dies. 
One  set — the  first — will  have  to  be  supplied  with  blank-holders 
and  a  die  having  a  rough  outline  of  the  required  design.  In  this 
die  the  metal  will  be  drawn  from  between  the  blank-holders  and 
into  the  die,  and  a  crude  impression  of  the  required  design  will 
be  given  it.  The  article  should  then  be  annealed  and  struck  up 
perfectly  in  a  finishing  die.  Not  infrequently  it  will  be  found 
necessary  to  use  three,  or  even  four,  sets  of  dies  to  accomplish 
the  desired  results  in  articles  which  are  excessively  deep.  Trays, 
salvers,  picture  frames  and  plates  having  ornamental  borders  not 
too  close  to  their  edges,  or  circular  articles  with  central  raised 
designs,  can  be  blanked  out  and  stamped  or  embossed  in  a  com- 
bination die  in  a  single-action  press,  the  die  being  equipped  with 
a  spring  buffer  and  a  blank-holder  ring,  or  in  a  double-action  die 
in  a  double-action  press.  Shallow  shells,  boxes  or  covers,  either 
circular  or  rectangular  in  shape,  can  be  blanked,  drawn,  formed, 
and  embossed  or  panelled  in  a  triple-action  die  in  a  double-action 
press  equipped  with  an  automatic  lower  punch  slide. 

To  fit  the  shanks  of  the  embossing  dies,  upper  and  lower,  or 
to  turn  the  outsides,  clamp  the  punch  or  "force "and  die  to- 
gether, and  then  machine  as  if  one  piece ;  thus  the  perfect  align- 
ment of  the  embossing  faces  with  each  other  when  the  die  is  in 
use  will  be  assured. 

Although  for  years  spoons,  forks,  and  embossed  metal  handles 
were  produced  under  the  drop  hammer,  this  method  has  now  be- 
come almost  obsolete,  as  the  improvements  in  heavy  automatic 
presses  and  feeding  devices  for  such  has  made  their  use  for  the 
production  of  such  articles  quite  general.  These  machines  pro- 
duce more  and  better  work  with  less  wear  on  the  dies  than  the 
drop  hammer. 


CHAPTER  XXX. 

The  Modern  Art  of  Swaging,  Swaging  Machines,  and 
the  Cold  Swaging  Process. 

THE   HAMMER. 

Man's  first  tool  in  shaping  metal  was  the  hammer,  and  with 
the  advancement  in  appliances,  during  the  centuries,  the  ham- 
mer has  continued  to  hold  its  place.     In  modern  metal  working 


Fig.  558. 


Fig.  559. 


the  hammer  is  supreme.  Its  form,  it  is  true,  is  changed  from 
time  to  time,  but  whether  the  hand  tool  or  the  power-driven 
hammer  is  considered,  the  principles  underlying  its  use  are  still 
the  same. 

The  simplicity  and  effectiveness  of  the  hammer  have  never 
been  excelled  in  any  other  tool,  nor  even  equalled.  Whether 
metal  be  worked  hot  or  cold,  the  hammer  is  the  king  of  tools. 
Not  only  does  the  hammer  produce  a  vast  amount  of  work  with 
a  small  expenditure  of  force,  but  it  gives  to  the  metal  qualities 
which  can  be  obtained  in  no  other  way.     Strength,  rigidity, 

479 


480  TOOL-MAKING   AND 

solidity,  and  increased  elasticity  are  all  gained  under  the  ham- 
mer, while  in  the  cases  of  iron  and  steel  a  surface  hardness  is 
secured  which  cannot  be  produced  in  any  other  manner. 

SWAGING   AND   HAMMEBING. 

Swaging,  however  performed,  is  only  a  kind  of  hammering. 
The  early  smiths,  it  may  be  supposed,  in  the  very  infancy  of  the 
race — certainly  long  before  the  dawn  of  history — observed  in 
working  the  metals  with  which  they  were  acquainted,  that  the 
face  of  the  hammer  always  left  its  impression  when  a  blow  was 


Fig.  560.— Pointing  for  Drawing. 

struck.  Any  irregularity  in  the  face  of  the  hammer  left  a  cor- 
responding mark  on  the  metal  struck.  To  this  fact,  undoubt- 
edly, does  modern  metal  working  owe  both  the  art  of  swaging 
and  the  art  of  die  sinking,  drop  forging,  and  embossing,  for  the 
fundamental  principle  in  each  is  that  of  making  a  special  face 
for  the  hammer  and  another  for  the  anvil. 

These  special  faces  for  the  hammer  and  the  anvil  are  given 
the  form  which  it  is  desired  to  impress  upon  the  metal,  which  is 
to  be  struck  between  them.  If  the  piece  of  metal  which  is  to  be 
worked  is,  for  example,  cj^lindrical  in  form,  the  face  of  each, 
the  hammer  and  the  anvil,  is  hollowed  out,  the  depression  being 
given  the  required  shape  or  design.  The  metal  worked  between 
them  is  then  forced  by  the  blows  applied  into  the  hollows  of  the 
two  faces,  thus  taking  on  the  desired  shape. 

While  it  may  be  supposed  that  the  first  swaging,  crude  though 
it  must  have  been,  was  performed  between  a  hammer  with  a  de- 
pression in  its  face  and  an  anvil  with  a  corresponding  indenta- 
tion, it  is  probable  that  it  was  not  very  long  before  the  early 
smiths  recognized  the  further  fact  that  a  great  gain  would  be 
made  in  such  work  by  separating  the  special  faces  from  the  ham- 
mer and  the  anvil,  respectively.     The  hammer,  therefore,  was 


INTERCHANGEABLE  MANUFACTURING.         481 

again  made  smooth  and  heated  to  be  struck  against  a  special  piece 
of  metal  or  false  face,  to  which  one-half  of  the  required  form 
had  been  given.  The  anvil,  instead  of  being  hollowed  out  ac- 
cording to  the  design  of  swaging  to  be  done,  was  made  a  large 
solid  block,  heavy  enough  to  resist  the  hardest  blows,  and  pro- 
vided with  means  to  receive  and  hold  a  second  special  face,  the 
counterpart  of  that  against  which  the  hammer  would  be  struck. 
What  are  now  known  as  swaging  tools  or  dies  resulted.  All  that 
has  been  accomplished  since  has  related  to  means  of  holding  tools 
to  be  operated,  to  means  of  imparting  the  necessary  blows,  and 
to  methods  of  controlling  and  guiding  the  work.  In  the  follow- 
ing the  matter  is  a  compilation  from  information  kindly  fur- 
nished the  author  by  the  Excelsior  Needle  Company,  of  Tor- 
rington,  Conn.,  manufacturer  of  the  Dayton  swaging  machine, 
and  the  technical  journal  Machinery. 

Strange  to  say,  the  ordinary  dictionaries,  in  defining  "swage  " 
in  the  sense  of  a  swaging  tool,  take  into  account  only  one  of  a 
pair  as  commonly  used  and  as  above  described.  One  definition, 
for  example,  is  as  follows:  "A  tool  having  face  of  a  given  shape, 
the  counterpart  of  which  is  imparted  to  the  object  against  which 
it  is  forcibly  impressed.  When  used  ...  it  is  either  placed 
on  the  anvil  so  as  to  impress  the  metal  which  is  laid  thereon 
and  struck  by  the  hammer,  or  the  work  being  laid  on  the  an- 
vil the  face  of  the  swage  is  held  upon  it  and  the  back  of  the 
swage  receives  the  blow."  But  modern  processes  of  swaging, 
work  the  metal  on  both  sides  or  all  around,  as  in  the  case  of 
a  rod  or  tube,  and  for  this  purpose  employ  both  top  and  bot- 
tom tools. 

The  use  of  false  faces  to  the  hammer  and  the  anvil,  as  above 
set  forth,  or  the  use  of  swaging  tools,  as  the  corrected  definition 
describes  them,  and  which  are  most  commonly  called  "dies," 
enables  a  number  of  blows  to  be  struck  in  obtaining  the  required 
result,  which  secures  an  important  economy  of  force,  while  also 
rendering  the  operation  less  trying  to  the  metal.  There  is  like- 
wise an  important  gain  in  the  quality  of  the  product.  Further, 
the  employment  of  dies  makes  possible  the  use  of  a  machine  for 
imparting  the  blows,  in  a  way  to  secure  rapidity  of  action  and 

absolute  uniformity  of  work.     The  force  of  the  hammer  is  trans- 
31 


482  TOOL-MAKING  AND 

mitted  through  the  movable  faces  or  dies  without  appreciable 
loss ;  in  fact,  with  a  positive  gaiu  in  various  points  of  effective- 
ness. 

THE   COLD-SWAGING  PROCESS. 

The  swaging  process,  although  extensively  used  in  certain 
classes  of  work,  is,  as  a  machine  shop  operation,  very  little  if  at 
all  recognized.  The  success,  however,  with  which  this  process 
is  employed  for  certain  purposes  would  seem  to  indicate  that  its 
use  might  be  applied  with  profit  to  a  great  class  of  work  that  is 
at  present  performed  either  by  hot  forging  or  by  machining. 

Cold  swaging  is  the  act  of  reducing  or  forming  steel  or  other 
material  while  cold,  such  as  drawing  to  a  point  or  reducing  the 
diameter  of  the  work.  This  is  performed  by  a  machine  which 
causes  the  work  to  be  struck  a  great  number  of  successive  blows 
by  a  pair  of  dies  of  suitable  shape  to  give  the  required  reduction. 
The  process  is  mainly  applied  to  reducing  wires,  rods,  and  tubes, 
and  is  the  only  process  by  which  rolled  or  plated  stock  can  be 
reduced  without  destroying  the  plating  or  coating.  For  this  rea- 
son it  is  largely  used  for  jewellers'  work,  such  as  forming  spec- 
tacle templets,  fancy  pins,  and  similar  pieces.  It  is  also  exten- 
sively used  for  pointing  rods  or  tubes  which  are  to  be  drawn. 
It  will  put  the  best  point  known  to  wire  drawers,  on  a  rod  or 
piece  of  wire  in  a  fraction  of  the  time  that  would  be  required  by 
any  other  method,  and  the  same  applies  to  its  use  on  tubing. 
The  millions  of  needles,  bicycle  spokes,  button  hooks,  crochet 
needles,  etc.,  which  are  turned  out  annually  serve  to  show  some 
of  the  possibilities  of  the  swaging  process. 

The  possibilities  of  the  swaging  process  are  almost  without 
limit.  The  blacksmith  through  the  ages  has  invented  unnum- 
bered applications  found  in  daily  use,  while  the  modern  ma- 
chine builder  has  discovered  various  means  of  adapting  swaging 
methods  to  the  rapid  and  economical  production  of  numerous 
shapes  and  forms  required  in  the  different  trades  and  industries. 

Eod-making  in  steel  and  iron,  as  well  as  the  kindred  trade  of 
making  bars  and  axles,  is  essentially  a  swaging  process.  There 
are  modifications  in  the  details  of  the  machinery  adapting  it  to 
the  purpose,  but  the  principle  is  the  same.     In  the  same  way  the 


INTERCHANGEABLE  MANUFACTURING.         483 

tapering  of  tubes  both  large  and  small  is  better  performed  by 
swaging  than  by  any  other  process.  Modern  swaging  as  a  means 
of  reduction  supersedes  rolling,  grinding,  milling,  turning,  and 


FIG.  561. 

drawing,  for  the  reason  that  it  improves  the  quality  of  the  mate- 
rial and  gives  greater  uniformity  and  better  surface  without 
waste  of  stock. 

One  of  a  pair  of  tools  or  dies  fastened  in  an  anvil  to  hold  the 
metal  to  be  worked,  and  the  other  sustained  above  it  and  adapted 
to  receive  the  blows  of  the  hammer,  constitutes  one  of  the  most 
useful  forms  of  swaging-machines.  Substitute  for  the  hand 
hammer  and  its  swinging  blows  a  series  of  machine-driven  ham- 
mers revolving  around  the  pair  of  dies  which  are  suitably  held, 
and  which  deliver  their  blows  in  pairs  upon  the  ends  of  the  dies, 
thus  forcing  them  together  and  against  the  metal  that  is  between 
them,  and  a  modern  machine  is  produced  the  product  of  which 
excels  in  character  and  value  anything  that  has  ever  preceded  it. 


484 


TOOL-MAKING  AND 


As  an  illustration  of  the  saving  of  stock  that  may  be  accom- 
plished by  the  use  of  this  process,  we,  will  consider  a  simple  piece 
of  rod  which  is  tapered  from  full  diameter  to  a  small  point,  as 


Figs.  562  and  563. 


shown  in  Figs.  562  and  563.  In  view  of  the  piece  marked  A,  the 
dotted  lines  show  the  original  piece  of  stock  from  which  it  would 
be  made  if  the  work  were  done  on  a  lathe  or  screw  machine,  by 


Fig.  564. 


the  machining  process,  the  dotted  section  showing  the  amount  of 
material  that  would  be  wasted.     In  the  lower  view  B,  the  dotted 


INTERCHANGEABLE  MANTJFA CTURING. 


485 


lines  show  the  amount  of  stock  that  would  be  required  to  pro- 
duce it  by  the  swaging  process,  and  there  would  be  no  waste 
whatever. 


ROTARY   SW AGING-MACHINES. 

The  rotary  swaging-machine  is  now  being  made  by  a  number 
of  manufacturers,  and  while  the  details  of  the  different  machines 
vary  in  some  respects,  the  principle  is  the  same  throughout. 
Representative  machines,  made  by  swaging-machine  builders, 
are  shown  in  Figs.  564  and  565. 

The  principle  of  the  modern  rotary  swaging-machine  is  shown 
in  the  line  drawing,  Figs.  558  and  559.  Inside  of  the  head  in  which 
the  spindle  revolves  is  a  set  of  hardened  steel  rollers  B  B  B  which 


Fig.  565. 

are  fitted  in  recesses  in  the  fixed  casting,  each  of  them  being  free 
to  run  on  its  own  axis.  The  front  end  of  the  spindle  A  is  large 
and  has  a  slot  across  its  face  in  which  the  hammer  blocks  slide. 
These  have  recesses  in  their  inner  ends  for  holding  the  dies  d  d, 


486 


TOOL-MAKING   AND 


and  in  their  outer  ends  are  the  rolls  E  E  which  are  free  to  turn 
when  they  come  in  contact  with  those  in  the  head.  As  the  spin- 
dle revolves  and  the  rolls  in  the  die-blocks  are  brought  into  con- 
tact with  those  in  the  head,  the  dies  are  forced  together  on  to  the 
stock.  After  passing  a  set  of  rolls,  the  dies  are  thrown  apart  by 
the  action  of  centrifugal  force,  which  keeps  them  separate  until 
the  next  set  of  rolls  is  encountered,  when  another  blow  results. 
The  machines  are  run  at  a  spindle-speed  of  from  400  to  500  revo- 
lutions per  minute,  and  as  there  are  eight  rolls  in  the  head,  the 
result  is  from  3, 200  to  4, 000  blows  of  the  die  per  minute.  The 
work  in  these  machines  is  not  rested,  as  the  rotation  of  the  spin- 
dle distributes  the  blow  evenly  around  the  circumference  of  the 


Samples  of  Work  Done  with  the  Rotary  Swaging  Machine. ' 
1-2.  Spectacle  Temples  (Steel)  7-8.  Machine  Needlesf  Steel) 

3.  Fancy  Pin  (Rolled  Stock)  9-10-11.  Cotton  Machine  Spindles 

i.  Ring  Body  (Plated  Stock)  (Hard  Steel) 

5-6.  Pin  Tongues  (Steel )  12.  Bitt  ( Steel) 

FIG.  566. 


piece  being  operated  upon.  In  another  type  of  machine  the 
rollers  are  replaced  by  oscillating  cams  which,  when  they  come 
in  line  with  the  ends  of  the  die- block,  form  a  powerful  toggle- 
joint  and  bring  the  dies  together  with  great  screws  which  cause 
the  wedges  back  of  the  cams  to  slide  in  toward  the  centre. 
Some  samples  of  the  work  done  with  the  rotary  machines  are 
shown  in  Fis;.  566. 


INTERCHANGEABLE  MANTJFA  CTTJB1NG. 


487 


THE  DAYTON   SWAGING-MACHINE. 

The  "Dayton"  swaging-niachine,  views  of  which  are  pre- 
sented in  Figs.  567,  568,  569,  and  570,  employs  dies  which  are  as 
simple  in  their  essential  features  as  the  most  primitive  swaging 
tools.  These  dies,  which  are  adjustable  in  their  relation  one  to 
the  other,  are  carried  in  a  slot  in  the  face  of  a  revolving  mandrel, 
and  are  held  between  a  pair  of  blocks  with  rounded  ends.  On 
the  side  of  and  around  the  mandrel  is  an  annular  rack  containing 
loosely  a  number  of  hardened  steel  rollers.     The  revolution  of 


FIG.  567. 


Fig.  508. 


the  mandrel  causes  the  dies  and  blocks  with  rounded  ends  to 
pass  between  successive  pairs  of  opposing  rollers  which  force 
the  dies  together.  The  mandrel  is  hollow  to  permit  the  work  to 
be  fed  through  it.  The  dies  revolve  rapidly  around  the  work, 
which  is  stationary,  while  the  rack  containing  the  rollers  revolves 
very  slowly,  being  moved  only  by  the  slight  motion  of  the  rollers 
during  the  time  of  contact  with  the  blocks.  Accordingly,  the 
effect  of  the  dies  is  very  evenly  distributed  about  the  work. 

The  dies  are  blocks  of  hardened  steel,  which  have  formed 
upon  their  inner  faces  the  impression  of  the  shape  or  the  diame- 
ter of  the  work  it  is  desired  to  produce,  with  an  enlargement  or 
flare  at  the  outer  or  entering  end  large  enough  to  allow  the  unre- 
duced stock  to  enter.  The  dies  are  set  up,  or  what  is  the  same 
thing,  the  blocks  with  rounded  ends,  or  the  backs  as  they  are 
called,  are  made  to  project  more  by  placing  thin  plates  of  steel 
between  the  ends  of  the  dies  and  the  backers.  The  dies  and 
backers  are  held  in  place  in  the  slot  in  the  face  of  the  mandrel 
by  suitable  plates. 

Referring  to  the  cuts,  Fig.  567  shows  a  face  view  or  front 


488 


TOOL-MAKING    AND 


elevation,  with  plates  removed,  and  Fig.  568  a  longitudinal  sec- 
tion of  one  of  the  smaller  sizes  of  the  Dayton  swaging-machine. 
The  working  parts  of  the  several  sizes  are  essentially  the  same, 
so  that  a  description  of  one  will  answer  for  all. 

Fig.  569  shows  the  roll  rack,  face  view,  cross-section  (one- 
half),  and  side  elevation  (one-half). 

Fig.  570  shows  the  face  of  the  mandrel  with  the  slot  for  re- 
ceiving the  dies  and  backers,  also  a  sectional  view  indicating  the 


Fig.  569. 


Fig.  570. 


central  aperture  for  receiving  the  work.  There  are  also  shown 
the  dies  B  in  both  side  and  end  views  and  backers  C.  The  plate 
used  for  holding  the  dies  in  place  is  shown  at  D. 

Eeferring  again  to  Fig.  568  it  will  be  seen  that  the  balance 
wheel,  and  fast  and  loose  pulleys,  are  attached  to  the  mandrel  at 
the  back,  and  that  the  mandrel  carrying  the  dies  revolves  within 
the  rollers  B;  also  that  the  roll  rack,  held  in  place  within  the 
cavity  of  the  head  of  the  machine  by  the  plate  F,  is  free  to  re- 
volve as  moved  by  the  backers  striking  the  rollers.  The  head  of 
the  machine,  which  is  of  cast  metal,  is  reinforced  by  a  wrought  - 
iron  ring,  shrunk  into  it  upon  the  outside,  and  by  a  hardened 
steel  ring  on  the  inside. 

The  mandrel  is  adapted  to  be  run  at  any  rate  of  speed  re- 
quired by  the  work  being  done.  With  five  pairs  of  rollers  in 
the  rack,  as  shown  in  Fig.  569,  there  will  be  ten  closures  of  the 
dies  to  each  revolution,  varied  only  by  the  slight  motion  im- 
parted to  the  rack  by  the  backers  striking  the  rollers.  Eunning 
at  a  speed  of  400  revolutions  per  minute,  therefore,  the  blows 
upon,  or  closure  of,  the  dies  will  approximate  4,000.  The  effec- 
tiveness of  the  machine  is  thus  made  apparent. 


INTERCHANGEABLE  MANUFA CTUFING. 


489 


HOBIZONTAL  SWAGING-MACHINES. 

The  horizontal  swaging-machine  was  originally  designed  by 
Mr.  John  Henderson,  of  Waterbury,  Conn.,  and  the  first  ma- 
chines were  built  by  him.  Later,  the  manufacture  was  trans- 
ferred to  the  Waterbury  Machine  Company,  by  whom  this  type 
of  machine  is  now  manufactured.  The  horizontal  is  especially 
designed  for  work  of  a  heavy  nature,  such  as  is  encountered  in 
mills  where  rods  and  tubing  are  manufactured.  It  is  constructed 
on  a  principle  entirely  different  from  that  of  the  rotary  machine. 
Fig.  571  shows  a  machine  of  this  type.  The  round  hole  at  the 
left,  in  line  with  the  upper  bearing,  is  the  opening  where  the  work 
is  introduced.  The  centre  of  this  hole  marks  the  place  where  the 
dies  are  split  on  the  vertical  line.  One-half  of  the  die  is  backed 
up  directly  against  the  heavy  casting  of  the  frame,  and  the  other 
half,  toward  the  bearing,  has  a  reciprocating  motion  on  the  hori- 
zontal line.  The  means  by  which  this  motion  is  obtained  will  be 
seen  by  reference  to  Fig.  571. 

The  lower  main  shaft  A  carries  the  balance  wheel  and  has  a 
crank  of  short  throw  between  the  bearings,  while  the  upper  shaft 
B,  of  large  diameter,  has  a  crank  with  a  throw  about  six  times  as 
great.     A  connection  C  joins  these  two  cranks;  it  will  turn  the 


Fig.  571. 


upper  shaft  through  but  a  portion  of  the  circle.  If  a  line  be 
drawn  through  the  centre  of  this  upper  shaft,  so  that  it  is  hori- 
zontal when  the  shaft  is  in  the  middle  portion  of  its  turn,  it  will 
follow  that  this  shaft  will  have  a  rocking  motion  about  its  cen- 
tre, and  the  diameterically  opposite  points  where  this  line  meets 
the  periphery  of  the  shaft  on  either  side  will  each  pass  the  centre 
twice  for  every  revolution  of  the  pulley.     If,  now,  a  system  of 


490  TOOL-MAKING   AND 

horizontal  toggles  be  interposed  between  the  reciprocating  block 
and  the  frame  casting  at  the  right,  in  which  system  the  middlle 
block  passes  through  the  shaft,  it  will  follow  that  by  the  rocking 
motion  of  this  block  the  distance  between  the  extreme  ends  will 
increase  and  decrease  twice  per  pulley  revolution,  or,  in  other 
words,  the  number  of  blows  will  be  twice  the  speed  of  the  pulley. 
A  spring,  not  shown  in  the  cut,  is  used  to  separate  the  dies  be- 
tween the  blows. 

These  machines  reduce  up  to  2-f  inches  in  diameter  and  tubes 
up  to  4  inches,  and  the  amount  of  reduction  ranges  from  ^  to 
\  inch  for  rods  and  -§■  to  -j  inch  for  tubes,  depending  upon  the 
diameter  and  nature  of  the  material.  Where  a  much  greater  re- 
duction is  required  than  can  be  made  by  passing  the  work  once 
through  the  dies,  it  has  proved  a  great  convenience  to  use  a  ma- 
chine with  three  sets  of  dies  which  gradually  decrease  in  size. 
This  is  brought  about  by  lengthening  the  machine  out  at  the  left- 
hand  end  for  two  extra  pairs  of  dies,  and  as  but  one  pair  is 
in  use  at  a  time,  motion  is  transmitted  from  one  set  to  the 
other,  all  having  a  sliding  fit  in  the  opening.  The  form  of  the 
die  is  a  cube,  so  that  four  faces  may  be  used  as  required,  the 
dies  being  turned  around  to  bring  similar  half -openings  together. 
When  small  diameters  are  required,  several  sizes  can  be  cut  on 
each  face,  and  the  changing  from  one  size  to  the  other  is  but  the 
work  of  a  moment. 

While  the  machine  is  principally  designed  to  point  rods  and 
tubes  for  subsequent  drawing  through  dies,  it  has  numerous 
other  uses,  such  as  flattening  round  stock  to  a  desired  shape  with- 
out waste  of  material.  In  this  way  it  has  been  successfully  ap- 
plied to  shaping  ends  of  rods  for  screw -driver  blades,  the  round 
rod  being  merely  pushed  into  the  opening  and  the  finished  article 
withdrawn  without  any  fin  or  waste.  Many  other  o}3erations  of 
a  similar  nature  may  be  performed,  and  in  this  class  of  work  it 
covers  a  ground  not  practicable  with  any  other  type  of  machine. 

SOME   EFFECTS   ON   WORK   ACCOMPLISHED    BY 
SWAGING. 

The  work  performed  by  the  swaging  process  is  done  by  press- 
ure rather  than  by  blows.     Accordingly,  there  is  a  flow  and  re- 


INTERCHANGEABLE  MANUFACTURING.         491 

adjustment  of  the  molecules  of  the  swaged  metal,  the  effect 
of  which  extends  equally  throughout  the  piece  in  a  manner  to 
strengthen  it  and  add  other  desirable  qualities.  To  perceive  the 
adaptability  of  the  machines  to  a  very  wide  range  of  work,  from 
articles  of  the  smallest  dimensions  up  to  those  of  a  considerable 
size,  requires  only  an  acquaintance  with  the  principle  upon 
which  they  operate. 


CHAPTER  XXXI. 

PROCESSES  AND  METHODS  FOE,  THE  WORKING 
OF  ALUMINUM. 

ALUMINUM   VS.  OTHEE   MEDALS. 

The  innumerable  uses  to  which  aluminum  has  been  put  dur- 
ing the  last  few  years,  and  the  large  variety  of  articles — from 
kitchen  utensils  to  drop  forgings — now  produced  from  its  vari- 
ous alloys,  promise  that  the  "beautiful  white  metal  "  is  destined 
to  be  very  extensively  employed.  Sheet  aluminum,  at  least,  is 
replacing  the  other  metals,  as  experiments  have  determined  that 
it  can  be  worked  as  expeditiously  and  economically  as  the  older 
commercial  sheet  metals.  It  can  be  worked,  when  of  a  proper 
alloy,  as  easily  as  sheet  brass,  German  silver,  or  tin-plate,  and  in 
numerous  instances — when  the  tools  have  been  made  correctly 
and  the  metal  is  lubricated  properly  while  working — it  can  even 
be  worked  more  cheaply  than  any  of  the  other  sheet  metals. 

DIFFICULTIES   ENCOUNTEEED   IN   WORKING. 

The  most  serious  difficulties  to  be  encountered  in  working 
aluminum  are  "hooking-in,"  clogging  and  squeaking,  in  drill- 
ing; tearing  and  "gouging-in, "  in  milling  and  planing;  "jam- 
ming" up  or  blocking  of  punchings  in  dies,  and  consequent 
breaking  of  punches;  the  cohesion  of  fine  particles  of  aluminum, 
compressed  hard,  to  the  cutting-edges  of  punches  and  inside  of 
dies,  and  on  bending  or  forming  dies  scratching  the  aluminum ; 
parting  or  breaking  the  metal  in  drawing  it. 

PUEE   METAL   VS.    ALLOYS. 

One  thing  that  a  great  many  mechanics  are  not  aware  of  is, 
that  aluminum  should  hardly  ever  be  used  in  its  pure  state. 
Many  of  those  who  have  experienced  difficulties  in  working  the 
metal  have  been  using  the  pure  metal  instead  of  a  suitable  alloy. 

492 


INTERCHANGEABLE  MANUFACTURING.         493 

A  majority  of  the  aluminum  alloys  compare  with  the  pure  metal 
about  as  brass  compares  with  copper,  and  as  brass  can  be  worked 
more  easily  than  pure  copper  so  aluminum  alloys  can  be  worked 
more  easily  than  pure  aluminum.  One  has  only  to  gaze  at  the 
variety  of  articles  and  novelties  which  may  be  found  in  a  shop- 
window  or  on  a  department-store  counter,  and  to  note  their 
cheapness,  to  understand  that  there  can  be  no  great  difficulty  in 
working  the  metal  into  any  shape  that  any  sheet  metal  will  flow  to. 

SECRETS   IN  THE  WORKING   OF   ALUMINUM. 

The  two  great  secrets— that  is,  if  we  may  term  them  secrets — 
in  the  working  of  aluminum,  either  in  its  pure  state  or  in  any  of 
its  alloys,  is  the  use  of  a  proper  lubricant,  and  in  the  proper 
shape  of  the  cutting-edges  of  the  tools. 

GRADES   AND   ALLOYS   OF    SHEET   ALUMINUM. 

There  is  a  great  variety  of  grades  and  alloys  of  sheet  alumi- 
num on  the  market,  so  numerous  that  no  difficulty  should  be  ex- 
perienced in  producing  that  suitable  for  any  special  purpose. 
Aluminum  may  be  had  in  much  the  same  variety  as  sheet  brass, 
or  in  all  degrees  of  hardness,  from  dead  annealed  stock  to  the 
pure,  stiff,  springy  aluminum.  Next  to  the  pure  metal  is  a  hard 
grade  of  alloys,  ranging  from  dead  soft  stock,  which  will  spin, 
draw,  or  form  up  hard  and  stiff,  to  the  same  grade  hard  rolled. 
After  that  comes  another  set  of  alloys  which  are  replacing  sheet 
brass  in  a  large  variety  of  kitchen  utensils,  novelties,  parts  of 
instruments,  mechanical  appliances,  and  the  lithographer's  stone. 
Lastly  there  is  another  grade  of  alloys  which  has  been  perfected 
lately  from  which  great  things  may  be  expected,  which  are  begin- 
ning to  be  used  for  drop-forgings.  Experiments  have  shown 
that  drop-forging  can  be  accomplished  with  this  metal  more 
easily  and  satisfactorily  than  with  many  others,  because  certain 
alloys  of  aluminum  can  be  worked  cold. 

WORKING  THE  METAL. 

Now  about  working  the  metal.  In  turning,  milling,  or  drill- 
ing aluminum  in  its  pure  state  more  difficulty  has  been  experi- 
enced than  in  the  press-working  of  the  sheet  metal.     All  these 


494  TOOL-MAKING   AND 

difficulties  disappear  if  the  tools  are  made  properly  and  the  right 
lubricant  is  used.  The  tool  should  be  made  with  lots  of  top 
clearance  and  bottom  rake,  and  instead  of  the  stub  point,  as  used 
for  brass,  it  should  be  lengthened  out.  The  top  clearance 
should  be  sufficient  to  allow  the  turnings  to  free  themselves 
easily  and  not  clog  around  the  point.  Lastly  the  tool  should  be 
tempered  at  a  light  straw,  and  stoned  to  a  keen  edge. 

LUBRICANTS   TO   USE. 

As  to  the  best  lubricants  to  use  for  the  machine  operations 
of  turning,  milling,  or  drilling,  crude  oil  is  best  for  milling  and 
kerosene  for  drilling ;  while  for  turning,  soap  water,  and  plenty 
of  it,  will  give  grand  resuls.  A  few  years  ago  a  large  number 
of  small  electric  cloth-cutting  machines  were  being  built  under 
my  supervision,  the  motor  eases,,  brackets,  standards,  and  bases 
of  which  were  castings  of  aluminum,  all  of  which  had  to  be  ma- 
chined all  over  to  interchange  perfectly.  A  number  of  fixtures 
were  constructed  for  their  production,  which  were  described  and 
illustrated  by  the  writer  iu  a  series  of  articles  in  the  columns  of 
the  American  Machinist  during  September  and  October,  1900, 
under  the  title  of  "Tools  for  Interchangeable  Work."  I  had  to 
do  a  great  deal  of  experimenting  to  produce  the  parts  to  the  re- 
quired degree  of  finish  and  interchangeability.  All  sorts  and 
shapes  of  cutting  tools  were  tried  and  different  lubricants  were 
used.  It  was  found  that  drills,  counterbores,  reamers,  centres, 
and  turning  tools  would  work  beautifully  when  iots  of  clearance 
was  given  them,  the  edges  being  well  hardened  and  then  stoned 
to  a  keen  edge;  that  soap  water  was  the  best  lubricant  for  drill- 
ing, and  for  large  counterboring  a  cheap  grade  of  vaseline. 
With  the  crude  oil  for  a  lubricant  in  milling,  butt  mills,  \  inch 
in  diameter,  were  used  to  take  deep,  wide  cuts  without  undue 
strain  on  the  teeth,  without  the  cuttings  clogging ;  and,  instead 
of  a  coarse,  torn  texture  resulting,  a  shiny,  smooth  finish  was 
the  pleasant  attainment.  In  one  large  shop  in  Brooklyn,  which 
makes  specialties  of  lithographing  presses,  bronze  machines,  and 
bronze  lithographing  dusting  machines,  they  formerly  used  large 
numbers  of  brass  brackets  for  the  grippers  on  the  presses,  but 
now  they  use  aluminum  castings. 


.INTERCHANGEABLE  MANUFACTURING.         495 

CUTTING  DIES   FOE  ALUMINUM. 

In  cutting  dies  for  aluminum  there  should  be  at  least  one  de- 
gree clearance.  If  the  blank  is  over  y1-^  inch  thick  and  a  smooth, 
uniform  edge  and  exact  size  of  blank  are  required,  it  should  be 
recut  or  "  shaved  "  in  a  second  die,  which  should  be  made  straight 
on  the  inside  cutting  edge  for  not  more  than  the  thickness  of  one 
block — or  two  at  the  most — in  order  that  the  die  may  retain  its 
exact  size  after  re-sharpening.  Allow  about  0.01  inch  on  the  out- 
side of  the  blank  for  shaving  to  ■£  inch  of  thickness,  but  if  the 
blanks  are  of  hard  aluminum  alloy,  half  that  amount  will  be 
sufficient. 

The  cutting-edges  of  both  punch  and  die  should  be  sharpened 
very  smoothly  after  grinding  with  an  oil  stone. 

Lard  oil  or  melted  Eussian  tallow,  the  best  for  lubrication, 
should  be  used  on  both  sides  of  the  metal. 

Punches  and  dies  should  be  carefully  cleaned  occasionally  of 
the  fine  particles  of  aluminum  that  will  be  found  adhering  to  the 
edges. 

DEA  WING-DIES   FOE   ALUMINUM. 

In  drawing  aluminum  of  a  thickness  not  more  than  -^  inch 
and  a  depth  of  draw  more  than  ^  inch,  to  avoid  the  tearing  or 
wrinkling  of  the  blank  it  should  be  held  between  a  ring  sup- 
ported on  pins  and  springs  and  the  face  of  the  punch,  rather 
than  between  the  edge  of  the  forming  cavity  of  the  punch  and 
the  sides  of  the  forming-block,  as  is  the  case  in  a  draw-plate  die; 
but,  however  it  may  be  held,  after  it  is  drawn  up  first  in  U-shape 
—redrawing  several  times  if  necessary  in  ordinary  draw-plates 
and  plungers — care  must  be  taken  not  to  employ  too  fast  a  speed 
in  the  operation,  or  the  work  will  break  at  the  bottom  through 
too  sudden  impact. 

If  the  aluminum  to  be  drawn  is  thicker  than  -g^  inch,  it  can 
be  drawn  direct,  without  the  spring  ring  mentioned  above,  to  a 
depth  of  f  inch,  or  even  deeper,  the  exact  depth  depending 
largely  of  course  upon  the  composition  of  the  aluminum  alloy, 
the  shape  of  the  article  to  be  produced,  the  finish  on  the  dies, 
and  the  speed  of  the  press. 


496  TOOL-MAKING  AND 

Aluminum  is  not  a  suitable  metal  to  work  in  compound  or 
sub-press  pieces,  as  the  number  of  pieces  of  this  metal  that  can 
be  punched  out  without  putting  the  dies  out  of  commission  by 
clogging*  and  consequent  breaking  of  punches  will  not  be  suffi- 
cient to  pay  for  the  cost  of  the  tools. 

DBA  WING   ALUMINUM   SHELLS. 

For  the  drawing  of  aluminum  shells,  tools  of  the  same  con- 
struction as  those  which  are  used  for  the  production  of  brass  or 
tin  ones  should  be  used.  One  peculiarity  of  aluminum  which 
manifests  itself  when  drawing  the  metal  is  that  one  cannot  ob- 
tain as  great  a  depth  with  it  in  one  operation  as  can  be  done 
with  brass.  This  is  because  the  tensile  strength  of  aluminum  is 
somewhat  less  than  that  of  the  other  metal.  It  may,  however, 
be  drawn  deeper  without  annealing  than  any  other  commercial 
metal.  An  article  made  of  brass  requiring,  say,  three  or  four 
operations  to  complete,  must  usually  be  annealed  after  each  re- 
drawing operation ;  conditions,  such  as  the  thickness  of  the  stock, 
depth  of  draw,  etc.,  determining  this.  With  aluminum,  how- 
ever, if  the  proper  grade  is  used,  it  will  often  be  found  possible 
to  perform  the  entire  number  of  operations  without  annealing  at 
all,  or  at  most  once.  At  the  same  time  a  finished  shell  will  be 
produced  which  will  be  equal  in  every  way  to  one  made  from 
sheet  brass. 

BENDING   AND   FOBMING   DIES    FOB   ALUMINUM. 

Bending  or  forming  dies  for  aluminum  should  have  all  the 
friction  parts  very  smooth  and  polished  in  the  direction  of  the 
draw  or  bend ;  that  is,  the  grain  of  the  die  and  punch  should  be 
in  the  direction  in  which  the  metal  travels  in  the  die.  Lard  oil 
should  be  used  on  both  sides  of  the  work. 

SFINNING   ALUMINUM. 

In  spinning  aluminum,  best  results  are  obtained  by  employ- 
ing a  high  speed,  with  a  light  pressure  of  the  spinning  tool, 
evenly  and  gradually  applied.  Aluminum  may  be  stamped 
under  a  drop-hammer  with  about  the  same  weight  and  momen- 
tum as  required  for  silver. 


INTERCHANGEABLE  MANUFACTURING.         497 


ANNEALING  ALUMINUM. 

Articles  of  aluminum  may  be  easily  annealed  by  heating  in 
an  ordinary  muffle,  taking  care  not  to  get  the  temperature  too 
high.  The  proper  annealing  heat  lies  between  650  and  700  de- 
grees Fahr.  The  best  test  for  the  heat  is  to  take  a  soft  pine  stick 
and  draw  it  across  the  metal.  When  the  wood  chars  and  a  black 
mark  is  left  on  the  metal,  it  is  sufficiently  annealed  and  is  in  the 
proper  condition  to  proceed  with  the  further  operations. 

POLISHING   AND   FINISHING   ALUMINUM. 

Next  to  the  working  and  machining  of  aluminum  the  most 
important  processes  lie  in  the  polishing  and  finishing  of  it. 
After  the  articles  have  been  produced,  a  fine  polish  can  be  given 
them  by  first  using  a  rag  buff  treated  with  tripoli  to  cut  down 
with.  The  high  finish  can  then  be  attained  by  using  a  dry  rouge 
that  comes  usually  in  lump  form,  first  grinding  it  to  as  fine  a 
powder  as  possible.  The  tripoli  also  should  be  very  finely 
ground. 

For  a  great  many  manufactured  aluminum  articles  a  frosted 
surface  is  desirable.  This  is  usually  done  by  scratch -brushes  made 
of  brass  crimped  wire  of,  say,  No.  31  to  No.  34  B.  &  S.  gauge. 
Three  or  four  rows  of  bristles  will  do.  To  lessen  the  work  of 
scratch -brushing,  the  metal  may  be  first  cut  down  with  a  por- 
poise-hide wheel  and  fine  Connecticut  sand,  the  sand  being  fed 
between  the  surface  of  the  wheel  and  the  article.  By  using  this 
latter  method  first,  the  skin,  pimples,  and  all  surface  irregularities 
are  removed,  and  the  scratch-brushing  is  made  easy.  When  the 
worked  metal  is  smooth  and  of  good  appearance  the  cutting 
down  with  tripoli  will  be  all  that  is  necessary,  after  which  the 
rouge  may  be  used  as  described,  and  tiiQ  finished  surface  put  on 
with  the  scratch-brush.  By  taking  the  preliminary  precautions 
the  scratch -brushing  will  frost  the  metal  quickly  and  uniformly. 

Another  way  of  obtaining  a  similar  effect  to  that  of  the 
scratch-brush  is  by  sand-blasting.     This  is  usually  done  to  the 
sheets  before  working  them,  first  sand-blasting  and  then  scratch- 
brushing.     The  effect  remains  after  the  articles  have  been  drawn 
32 


498  TOOL-MAKING  AND 

up,  as  the  metal  works  in  much  the  same  maimer  as  lithograph 
sheets  would,  in  the  working  of  which,  as  is  well-known,  the 
designs  are  not  marred. 

There  is  still  another  method  for  producing  a  very  pretty 
frosted  effect  on  aluminum.  It  consists  of  first  sand-blasting 
and  then  frosting  by  "dipping."  A  great  many  varieties  of 
finish  on  aluminum  can  be  obtained  by  suitable  combinations  of 
these  treatments. 

To  secure  a  pretty  mottled  effect  on  aluminum  the  article 
should  first  be  polished,  then  the  scratch  brush-applied,  and  then 
the  surface  burnished  with  a  soft  pine  wheel  which  should  be 
run  at  a  very  high  rate  of  speed.  By  careful  manupulation  regu- 
lar or  irregular  patterns  of  mottling  can  be  obtained. 

The  cheapest  and  most  economical  way  of  producing  articles 
with  finished  surfaces  from  the  sheet  is  to  treat  the  sheets  as 
follows :  After  removing  all  grease  and  dirt  from  the  metal  by 
dipping  in  benzin,  cleanse  in  water  until  the  benzin  has  disap- 
peared, after  which  the  plates  may  be  dipped  in  a  strong 
solution  of  caustic  soda,  or  caustic  potash,  holding  them  in  the 
solution  until  they  commence  to  turn  black.  Then  remove  the 
sheets,  dip  again  into  water,  and  then  into  a  solution  of  concen- 
trated nitric  and  sulphuric  acids.  After  removing  from  this 
last  bath,  wash  the  sheets  thoroughly  in  water,,  and  dry  in  hot 
sawdust.  The  finish  on  the  plates  can  be  varied  by  varying  the 
strength  of  the  caustic  solution,  or  by  adding  a  small  quantity  of 
salt  to  the  full -strength  solution. 

BUKNISHING. 

For  articles  which  require  to  be  burnished  a  steel  burnisher  or 
a  bloodstone  will  give  the  best  results.  When  burnishing  the 
use  of  a  mixture  of  melted  vaseline  and  crude  oil  as  a  lubricant, 
or  a  solution  composed  of  three  tablespoons' of  borax  dissolved 
in  a  quart  of  hot  water  with  a  few  drops  of  ammonia,  will  add 
to  the  finish  of  the  work. 

ENGEAVING  AND   CHASING  ALUMINUM. 

A  great  deal  of  engraving  is  now  being  done  on  aluminum, 
such  as  on  finished  picture-frames,   cups,   trays,   book-covers, 


INTERCHANGEABLE  MANUFACTURING.         499 

match-safes  and  similar  articles,  and  for  this  work  the  best  lubri- 
cant to  use  on  the  tools  is  naphtha  or  crude  oil.  A  mixture  of 
crude  oil  and  vaseline  also  is  good.  However,  the  naphtha  will 
be  found  the  best,  as  it  will  not  affect  the  satiny  finish  around 
the  edges.  Besides  the  use  of  a  proper  lubricant  when  engrav- 
ing aluminum,  considerable  skill  is  necessary  in  the  making  and 
use  of  the  cutting-tool.  A  tool  made  similar  to  a  turning  tool 
for  aluminum,  finished  to  a  sharp,  keen  point  with  lots  of  clear- 
ance, will  work  excellently. 

A  property  that  makes  pure  aluminum  very  valuable  for 
many  purposes  lies  in  its  ability  to  withstand  the  action  of  acids. 
While  the  metal  is  easily  affected  by  alkalies,  the  strongest 
acids  do  not  injure  it  to  any  noticeable  extent — in  fact,  acid  acts 
on  it  in  much  the  same  manner  as  on  platinum.  For  parts  of 
apparatus  which  have  to  be  immersed  in  strong  acids  for  consid- 
erable periods,  parts  of  aluminum  will  prove  highly  efficient. 
One  use  to  which  the  metal  has  been  put  in  this  respect  is  for 
hooks  for  removing  photographic  negatives  from  the  acid  baths. 
Acid  funnels  of  aluminum  also  have  proved  a  boon  to  many. 

SOLDEEING  ALUMINUM. 

The  last,  but  not  by  any  means  the  least  valuable,  process  in 
the  working  and  use  of  aluminum  is  soldering.  To  many  the 
difficulties  experienced  in  this  line  have  proven  a  great  detri- 
ment to  the  successful  use  of  the  metal  for  many  purposes.  The 
uncertainty  as  to  the  best  solder  to  use  has  been  one.  There  are 
any  number  of  solders  which  have  proved  fairly  successful  when 
skill  has  been  employed  in  using  them.  The  following  has 
proven  to  be  the  best  in  practice  for  soldering  the  pure  metal  or 
any  of  its  alloys :  Fuse  together  one  pound  of  block  tin,  four 
ounces  of  spelter,  two  ounces  of  pure  lead,  three  pounds  of 
phosphor  tin.  With  benzin  clean  all  dirt  and  grease  from  the 
surfaces  of  the  parts  to  be  soldered  and  then  apply  the  solder 
with  a  heated  copper  "iron."  When  the  melted  solder  covers 
the  surfaces  completely,  scratch  through  it  with  a  wire  brush, 
which  will  break  the  oxide  and  take  it  up.  Spread  the  solder 
again  with  the  iron  and  allow  to  cool.  When  it  is  found  neces- 
sary to  "sweat"  aluminum  parts  together,  first  clean  the  surfaces 


500  TOOL-MAKING. 

as  described  for  soldering,  then  heat  the  parts  until  the  solder 
flows  freely  over  them,  scratch  through  with  the  wire  brush, 
wipe  with  clean  waste,  and  clamp  together.  A  first-class  joint 
will  result. 

ALUMINUM   AS   AN  ABEASIVE. 

Aluminum,  despite  its  metallic  character,  can  be  used  as  an 
abrasive  for  sharpening  knives.  It  has  the  structure  of  a  deli- 
cately grained  stone,  and  under  friction  gives  an  extremely  fine 
mass  which  adheres  powerfully  to  steel.  Consequently,  blades 
sharpened  on  aluminum  rapidly  take  a  thin,  sharp  edge  which 
cannot  be  produced  by  the  best  stones.  If  knives  are  passed 
with  utmost  care  over  a  razor  stone,  the  edge,  when  magnified 
1,000  times,  shows  irregularity  and  toughness,  while  edges  pro- 
duced on  aluminum,  when  submitted  to  the  same  examination, 
appear  perfectly  straight  and  smooth. 


CHAPTER  XXXII. 

Hints,  Kinks,  Ways,  and   Methods   of  Use   to  Tool- 
makers  and  Die -makers. 

NOTES   ON   CIRCULAR  FORMING   TOOLS. 

When  making  circular  forming  tools  always  keep  the  fact  in 
mind  that  the  diameter  has  much  to  do  with  their  wearing  quali- 
ties; and  that  unless  their  diameter  is  proportionate  to  the  diam- 
eter of  the  work  satisfactory  results  will  be  hard  to  obtain. 

In  Fig.  572  are  shown  two  circular  tools  of  H  and  2  inches 
diameter,  respectively,  both  cut  out  ^  inch  below  centre,  as  they 
would  be  if  intended  to  operate  on  the  front  side  of  the  machine 


D 


Fig.  572. 

or  at  the  back  side  with  the  work  running  backward.  Although 
shown  in  this  position,  the  principle  involved  is  of  course  the 
same  as  though  the  tools  were  placed  the  other  side  up,  the  tool- 
post  being  bored  out  above  the  centre-bore  of  work  spindle,  in- 
stead of  below,  as  in  the  case  referred  to. 

Referring  to  Fig.  572  it  is  easy  to  see  that  the  cutting-edge  of 
the  larger  tool  would  have  much  greater  endurance  than  that  of 
the  smaller,  the  rake  or  clearance  of  the  latter  being  excessive. 
This  difference  of  rake  in  circular  cutters  must  of  course  in- 
crease with  the  difference  in  diameter  of  the  cutters,  provided 
the  cutting-edges  are  located  at  the  same  distance  from  centre. 
The  case  is  similar  to  that  in  Fig.  573,  where  are  shown  side  by 

501 


502 


TOOL-MAKING  AND 


side  two  straight  cutting-off  tools,  the  clearance  of  one  ground 
as  at  E  and  the  other  as  at  F.  The  angle  of  clearance  of  B  is 
practically  the  same  as  that  of  the  larger  circular  tool  in  Fig. 


Fig.  573. 

574,  while  that  of  F  coincides  with  that  of  the  smaller  tool  and 
shows  much  less  durability  than  the  tool  ground  as  at  E. 

It  is  usually  the  best  practice  in  making  tools  for  a  certain 
size  machine  to  keep  them  as  closely  to  one  diameter  as  possible. 
In  the  larger  machines  cut  out  the  tool  T\  inch  from  centre, 
and  of  course  bore  the  tool-post  a  corresponding  amount  above 
or  below  the  centre,  according  to  which  side  up  the  tool  is  to  be 


D 


Fig.  574. 

operated.  For  the  smaller  machines  make  the  tools  of  less  diam- 
eter, cutting  them  out  £  inch  from  centre  and  boring  the  post  to 
correspond.  In  Fig.  574  line  A  B  represents  centre  of  work,  CD 
centre  of  large  cutter,  showing  the  same  cut  T3g  inch  below  cen- 
tre, while  G  D  represents  centre  of  small  cutter  and  shows  the 
same  cut  £  inch  below  centre.  The  clearance  of  both  cutters  is 
practically  identical. 

A   KINK  FOE   DEAWN  WORK. 

A  sharp  corner  under  a  shoulder  or  flange  is  often  a  very  de- 
sirable thing,  and  one  generally  considered  impossible  in  drawn 


INTERCHANGEABLE  MANVFA  CTUBING. 


503 


work  because  of  the  necessity  of  a  round  corner  on  the  die  to  keep 
the  metal  from  tearing-  while  being  drawn  through  the  die.  There 
is  a  method,  however,  of  doing  this  that  is  quite  successful,  as 
shown  by  the  accompanying  sketch,  and  it  seems  to  be  about  the 
only  way  it  can  be  done.  The  "kink"  consists  in  making  the 
punch  a  series  of  steps  as  per  Fig.  575,  with  round  corners  instead 
of  a  parallel  one,  as  in  the  usual  j)ractice ;  the  steps  to  be  about  as 
far  apart  as  the  depth  to  be  drawn ;  and  the  difference  in  diame- 
ter of  steps  to  be  determined  by  thickness  of  stock.  The  blank, 
instead  of  being  a  round  disk,  is  a  washer,  the  outer  edges  held 
not  too  tightly  by  the  usual  pressure  ring  or  plate,  and  the  end  of 
the  punch  to  be  a  little  larger  than  the  hole  in  the  washer.     The 


'     '  'in 


SECTION  OF  DIE 
V//////////////.-::'//-'':'-[-PR£SS{JRE  RING 


"     -DIE  PLATE 


Fig.  575. 


punch  will  open  the  hole  to  the  full  diameter  of  the  end  and  turn 
the  sharp  corner  of  the  disk  in  the  most  surprising  manner.  The 
steps  follow  each  other  rapidly,  each  one  enlarging  the  hole  to 
its  own  size  and  carrying  the  stock  down  through  the  die,  the 
last  step  being  the  finished  size  of  the  interior  of  work,  and  the 
hole  in  the  dies  being  the  outside  diameter  of  same.  A  die  like 
this  needs  a  press  with  a  good  long  stroke,  dej)ending,  of  course, 
upon  the  character  of  the  work. 

BEASS-WOEKENTG  TOOLS   AND   THEIE  USE. 

Figs.   576  to   583   illustrate  brass- working    tools  for   hand 
work.     No.  576  is  a  flat  planishing  tool  which  is  used  for  finish- 


504 


TOOL-MAKING  AND 


iug  and  smoothing  down  flat  surfaces,  and  also  convex  surfaces. 
No.  577  is  a  flat  planisker,  ground  at  an  angle  so  as  to  allow  of 
getting  into  a  corner.  Nos.  578  and  579  are  for  finishing  in  round 
corners  or  roughing  concave  surfaces.  No.  580  is  a  small  round- 
nose  tool  which  is  generally  used  for  roughing  out  work  or  get- 


FiGS.  576  to  583. 


ting  under  the  scale  of  a  casting.  No.  581  is  the  proper  form 
of  hand  cutting-off  or  parting  tool.  None  of  these  tools  should 
have  any  top  rake;  on  the  contrary,  they  should  be  ground 


Figs.  584  to  591. 

slightly  the  other  way  and  carefully  stoned  on  an  oil  stone. 
Nos.  582  and  583  are  hand  thread  chasers,  which  are  respectively 
for  outside  and  inside  threads. 

The  tools  shown  in  Figs.  584  to  591  are  for  use  in  the  Fox 
lathe.  The  hook  tools  which  are  used  in  the  back  head  of  the 
machine  closely  resemble  the  regular  inside  tools,  except  that 
the  point  is  turned  the  other  way  for  outside  work.     Sometimes 


INTERCHANGEABLE  MANUFACTURING.         505 

a  tool-holder  similar  to  that  shown  with  set-screw  is  used  with 
small  inserted  cutters.  Give  these  tools  no  top  rake  and  no 
difficulty  will  be  encountered  in  their  use. 

By  grinding  a  twist  drill  as  indicated  at  B  all  danger  of 
drawing-in  will  be  avoided ;  that  is,  grinding  the  lips  flat  for  a 
short  distance.  On  a  small  drill  the  whole  point  may  be  ground 
flat  to  obtain  the  best  results. 

The  flat  hand  drill  illustrated  is  the  best  for  rough-boring  a 
hole  in  a  solid  piece.  A  series  of  such  are  used  for  taper  holes, 
the  larger  being  used  first  and  the  others  following  to  the  proper 
depth  to  make  about  the  required  taper.  This  is  then  reamed 
out  to  the  exact  taper  with  various  tools.  A  flat  reamer  is  often 
employed  with  good  results,  especially  for  roughing.  For  finish- 
ing it  is  very  apt  to  chatter  unless  packed  on  each  side  with  a 
piece  of  hard  wood  of  about  the  right  shape  to  conform  to  the 
hole.  Sometimes  a  reamer  with  a  single  large  flute,  as  shown,  is, 
used  with  good  results.  It  is  relieved  nearly  all  the  way  around. 
For  finishing,  it  is  hard  to  beat  the  old  reliable  square  reamer 
as  shown  at  590.  This  reams  a  nice  smooth  hole  as  it  fills  up 
with  chips  enough  to  prevent  chattering,  and  it  starts  well  if 
carefully  ground  and  honed  on  an  oil  stone. 

GRINDING   TWIST  DRILLS   FOR   CUTTING   A   SECTION 

OF   A   HOLE. 

In  order  to  drill  holes  in  which  part  of  the  drill  has  to  cut  a 
section  of  a  hole  as  shown  in  the  sketches  Figs.  592  and  593  the 
drill  should  be  ground  as  shown  in  Fig.  593.  It  will  then  be 
found  as  easy  to  drill  the  holes  straight  as  if  drilling  a  full  hole. 

To  start  the  drill,  use  an  ordinary  drill,  drilling  just  deep 
enough  to  enter  the  blades  of  the  drill  as  ground  in  Fig.  593 ;  or 
a  jig  may  be  used  to  guide  the  drill  in  starting. 

TURNING  AND  TRUING  RUBBER. 

The  medium-hard  compositions  of  rubber  work  very  nicely 
with  a  diamond-point  tool,  ground  a  little  round  on  the  point 
and  given  a  sharp  rake.  The  tool  should  be  hardened  very  hard, 
as  there  is  sufficient  fine  grit  in  the  rubber  to  wear  the  edge 


506 


TOOL-MAKING  AND 


badly.  The  speed  is  governed  by  the  ability  of  the  tool  to  stand 
up  to  the  work,  and  is  slower  in  proportion  as  the  rubber  is 
harder. 

Soft-rubber  articles  cannot  be  cut  satisfactorily  with  any  kind 
of  a  tool ;  the  best  and  quickest  way  is  to  grind  them  down.  In 
fact,  grinding  makes  the  most  satisfactory  job,  whether  the  rub- 
ber is  hard  or  soft. 

The  grinding  may  be  done  in  a  lathe,  using  an  overhead  drum 
for  driving  the  wheel  and  bolting  the  wheel  arbor  to  the  tool- 
post  block. 

In  plants  where  electricity  can  be  had  a  small  direct-con- 
nected motor,  with  flexible  cord  and  plug,  makes  the  most  con- 


FiG.  593. 


venient  drive,  as  it  is  readily  detached  and  put  away  when  not 
in  use,  leaving  plenty  of  head  room  over  the  machine,  a  quite 
important  detail  in  shops  where  most  of  this  work  is  done,  and 
where  one  or  two  lathes  have  to  do  all  the  work,  large  and  small. 
The  best  results  are  obtained  by  using  cast-iron  disks  for 
wheels,  8  to  10  inches  in  diameter  and  1\  inches  thick,  with  a 
groove  1  inch  wide  and  ^  inch  deep  turned  in  the  face.  This 
groove  is  filled  with  strong  twine,  laid  on  tight  in  hot  glue  and 
then  covered  with  several  coats  of  glue  and  No.  40  emery. 
These  wheels  are  to  run  dry. 


INTERCHANGEABLE  MANUFACTURING. 


507 


PATENT   TOOL-HOLDERS. 

Figs.  594  to  600  show  a  complete  set  of  the  tools  that  with  a 
straight  tool-holder  will  accomplish  all  ordinary  lathe  work. 

In  grinding  these  tools  always  take  them  out  of  the  holder, 
otherwise  they  will  be  too  heavy  and  liable  to  heat  when  placed 
against  the  emery  wheel.     If  the  cutter  alone  is  held  in  the  hand 


<^s 


FIGS.  591  to  600. 


it  gives  timely  warning,  by  becoming  too  hot  to  hold  comforta- 
bly, and  is  cooled  off  before  it  gets  hot  enough  for  the  temper  to 
be  drawn. 

HARD-SOLDERING. 

In  the  operation  of  hard-soldering,  if  the  action  of  heat  and 
the  nature  of  the  metals  in  hand  are  understood,  there  should  be 
no  trouble  in  obtaining  a  good  sound  joint,  provided  the  proper 
facilities  are  available.  Jewellers,  as  a  rule,  are  very  painstak- 
ing in  their  preparatory  work,  rubbing  borax  paste  upon  slate, 
exercising  great  care  to  avoid  touching  the  joint  with  the  hands, 
so  as  to  have  chemically  clean  metallic  surfaces,  etc.  This  is  all 
correct,  theoretically,  but  some  machinist  workmen  also  pay  all 
attention  to  these  details,  and  yet  lose  sight  of  the  more  impor- 
tant fundamental  principles,  especially  those  pertaining  to  tem- 
perature. In  a  large  portion  of  the  hard-soldering  to  be  done  in 
the  average  shop,  the  observance  of  these  minor  details  first 
referred  to  would  involve  considerable  trouble.  These  may  be 
safely  ignored  to  a  large  extent  if  the  applications  of  flux,  solder, 
and  temperature  are  properly  made. 

Have  the  joint  as  tight  as  possible,  to  prevent  the  solder  from 
running  through  without  filling.  Apply  the  flux  paste  before  any 
heating  is  done,  and  do  not  put  the  solder  on  until  the  work  is 
about  a  low  red  heat,  depending  on  the  character  of  the  work, 


508  TOOL-MAKING  AND 

metal,  shape,  etc.  Apply  the  heat  to  the  joint  rather  than  to 
the  solder,  and  if  the  solder  runs  immediately  as  it  is  used,  have 
no  fears  as  to  the  success  of  the  job.  In  cases  where  a  joint  can- 
not be  drawn  tight,  fill  up  with  wire,  scrap  metal,  fillings,  etc., 
of  the  same  metal  as  the  work.  This  may  also  be  applied  to  the 
outside  of  the  joint  if  it  is  desired  to  retain  solder  for  reinforce- 
ment. 

If  these  rules  are  adhered  to,  it  will  be  unnecessary  to  mix 
your  flux  paste  on  slate,  and  slight  fingering  will  not  prevent 
the  making  of  a  good  joint.  However,  cleanliness  is  a  trait  to 
be  cultivated,  and  is  desirable  in  all  soldering  operations.  If 
the  joint  is  not  reasonably  clean,  solder  will  not  flow  readily, 
more  being  required  to  dispel  or  vaporize  the  grease  or  other 
foreign  matter. 

SPEED   OF   PULLEYS   AND   GEAES. 

In  any  system  of  pulleys  or  gears  the  general  rule  holds  that 
the  product  of  the  diameters  or  number  of  teeth  of  the  driving 
wheels  and  the  number  of  revolutions  per  minute  of  the  first 
driver  must  equal  the  product  of  the  diameters  or  number  of 
teeth  of  the  driven  and  the  number  of  revolutions  per  minute  of 
the  last  driven  wheel. 

The  most  frequent  pulley  calculations  in  the  machine-shop  re- 
late to  the  speeds  of  machines  and  countershafts,  for  which  we 
have  the  four  following  rules,  based  upon  the  above  principle. 

First,  speed  of  pulley  on  machine  given,  to  find  speed  for 
countershaft.  Multiply  the  number  of  revolutions  per  minute 
of  the  machine  pulley  by  its  diameter  and  divide  this  product  by 
the  diameter  of  the  driving  pulley  on  the  countershaft. 

Second,  speed  of  countershaft  given,  to  find  the  diameter  of 
pulley  to  drive  machine.  Multiply  the  number  of  revolutions 
per  minute  of  the  machine  pulley  by  its  diameter,  and  divide 
the  product  by  the  number  of  revolutions  per  minute  of  the 
countershaft. 

Third,  speeds  of  main  shaft  and  of  countershaft  given,  to  find 
diameter  of  pulley  on  countershaft.  Multiply  diameter  of  main 
pulley  and  divide  by  number  of  revolutions  per  minute  of  coun- 
tershaft. 


INTERCHANGEABLE  MANUFACTURING.         509 

Fourth,  speed  of  countershaft  given,  to  find  diameter  of 
pulley  for  line  shaft.  Multiply  number  of  revolutions  per  min- 
ute of  the  countershaft  by  the  diameter  of  the  pulley  belting 
with  the  main  line,  and  divide  the  product  by  the  number  of 
revolutions  per  minute  of  the  line  shaft. 

ETCHING   STEEL. 

For  etching  names,  dates,  designs,  etc.,  in  steel,  use  any  of 
the  following  recipes: 

No.  1. — Iodine,  2  parts;  potassium  iodide,  5  parts;  water,  40 
parts. 

No.  2. — Nitric  acid,  60  parts;  water,  120  parts;  alcohol,  200 
parts ;  copper  nitrate,  8  parts. 

No.  3. — Glacial  acetic  acid,  4  parts;  nitric  acid,  1  part;  al- 
cohol, 1  part. 

BOEING    LONG   CAST-IRON   TUBES. 

When  boring  long  cast-iron  tubes  of  large  diameter — say  15 
inches — excellent  results  may  be  attained  by  using  kerosene  as  a 
lubricant,  and  a  "packed  bit"  of  the  type  used  for  gun-boring. 
Holes  of  the  smoothness  of  glass  will  be  the  result. 

TINNING   CAST   IRON. 

The  following  tinning  for  cast  iron  will  turn  out  whiter  and 
harder  than  that  with  tin  alone :  Iron,  6  parts ;  tin,  85  grammes ; 
nickel,  9  grammes.  Dissolve  the  three  metals  in  hydrochloric 
acid.  This  alloy  will  adhere  well  to  the  cast  iron  and  present  a 
very  brilliant  surface. 

All  tanks  used  for  pickling  cast  iron  in  vitriol  should  be  lined 
with  lead  and  the  seams  burned  together,  not  soldered.  When  a 
pickling  tank  is  lined  with  zinc  it  will  last  but  a  short  time 
under  the  action  of  the  acid.     Solder  is  also  acted  upon. 

A  HANDY   DIE  AND    TOOL-MAKER'S   CLAMP. 

In  Fig.  601  are  shown  sketches  of  a  very  handy  clamp.  It 
may  be  used  for  many  purposes  other  than  the  one  indicated. 
In  this  case  it  does  away  with  the  making  of  templets  in  die- 


510 


TOOL-MAKING  AND 


making  after  the  master  blank  has  been  made.  First,  the  exact 
centre  of  the  die  blank  is  found ;  then  the  blank  is  placed  in  its 
proper  position  on  the  face  and  clamped  there  as  shown  in  the 
sketch.     Then  the  outline  of  the  blank  is  scribed. 

The  clamp  may  also  be  used  to  hold  the  steel  block  for  the 


Fig.  601. 

punch  securely  against  the  die  face ;  thus  facilitating  the  turning 
of  the  work  to  the  light  and  examining  the  inside. 

LUBRICANT   FOR  DRAWING   SHELLS. 

Take  one  pint  of  common  lard  oil,  two  pounds  of  opodeldoc 
soap,  eight  gallons  of  water ;  steam  or  heat  until  warm.  Attach 
a  square  pan  to  the  front  of  the  press  and  keep  the  shells  well 
covered.  With  very  small  shells,  such  as  primers  or  pencil  tips, 
it  will  be  necessary  to  keep  the  solution  warm ;  but  with  large 
shells  this  will  not  be  necessary.  This  is  the  best  lubricant  for 
drawing  shells  from  thin  metal  that  I  have  ever  come  across. 

TO   GLITE   LEATHER  TO   IRON. 

To  glue  leather  to  iron,  paint  the  iron  with  some  kind  of  lead 
color,  say  white  lead  and  lamp-black.  When  dry,  cover  with  a 
cement  made  as  follows :  Take  the  best  glue  procurable,  soak  it 
in  cold  water  till  soft,  then  dissolve  in  vinegar  with  a  moderate 
heat,  then  add  one-third  of  its  bulk  of  white  pine  turpentine, 
thoroughly  mix,  and  by  means  of  vinegar  make  it  the  proper 
consistency  to  be  spread  with  a  brush.     Apply  the  cement  while 


INTERCHANGEABLE  MANUFACTURING.         511 

hot ;  draw  the  leather  ou  or  around  quickly,  and  press  tightly  in 
place.  In  case  of  a  pulley,  draw  the  leather  around  tightly  as 
possible,  lay  and  clamp. 

KEEPING    NOTEBOOKS. 

Before  concluding  this  chapter  I  feel  that  it  will  be  well  to 
present  a  few  remarks  on  the  advantage  of  keeping  note-books 
in  which  to  note  and  preserve  the  valuable  and  useful  informa- 
tion which  abounds  in  the  mechanical  press  and  which  one  be- 
comes informed  of  through  association  with  brother  mechanics, 
or  through  experience  and  practical  observation.  It  is  a  fact 
that  the  diffusion  of  knowledge  is  retarded  greatly  by  mechanics 
in  general  trusting  to  their  memory  for  the  preservation  of  valu- 
able information,  instead  of  to  more  reliable  means. 

The  most  simple  way  to  gain  by  one's  reading  and  observa- 
tion is  to  determine  to  fix  upon  some  plan  within  one's  capacity, 
means,  and  opportunity — those  which  come  in  one's  daily  routine 
— and  to  follow  it  j>reseveringly,  regularly,  and  punctually,  as  an 
important  factor  in  one's  daily  duties.  Many  men  owe  their  suc- 
cess in  life  to  the  keeping  of  note-books  in  which  they  had  noted 
information  which,  while  of  little  moment  at  the  time  when  writ- 
ten, proved  of  inestimable  value  at  a  later  date. 

A  good  way  is  to  keep  three  note- books :  one  for  jotting  down 
items  and  notes  and  sketches  which  come  to  one  in  the  shop 
through  observation,  hearsay,  and  experience.  This  book  should 
be  of  pocket  size.  The  second  book  should  be  a  large,  strongly 
bound  manuscript  book  having  horizontal  ruled  lines.  In  this 
one  can  write  something  every  evening — something  one  has  read 
in  a  mechanical  paper.  The  third  book  may  be  a  scrap-book  of 
the  usual  kind,  in  which  sketches,  small  drawings,  diagrams,  and 
illustrations  of  new  machines  and  appliances  may  be  pasted.  By 
following  this  suggested  plan  one  will  become  a  close  and  accu- 
rate observer,  an  enlightened  and  well-informed  man,  and  a  bet- 
ter mechanic ;  no  matter  what  line  he  is  engaged  in,  he  will  not 
only  gain  in  knowledge,  but  may  gain  financially  by  publishing 
in  the  mechanical  press  any  information  which  has  come  to  him 
through  experience  and  observation  and  which  appears  to  be 
new  or  novel. 


CHAPTER  XXXIII. 

The  Value  of  Up-to-date  Fixtures  and  Machine 
Tools. — Conclusion. 

In  the  preceding  chapters  I  have  endeavored  to  illustrate  and 
describe  the  most  approved  construction  and  methods  for  accom- 
plishing the  best  results  in  modern  tool-making  and  interchange- 
able manufacturing ;  and  before  drawing  this  work  to  a  close  I 
have  thought  it  fitting  to  conclude  by  discussing  the  value  of  im- 
proved and  labor-saving  fixtures  and  machines,  and  to  present 
what  to  me  appears  to  be  the  only  system  by  which  the  Ameri- 
can machine-shop  or  manufacturing  plant  can  retain  its  place  at 
the  head  of  the  world's  list  of  industrial  supremes. 

LACK     OF   KNOWLEDGE   OF   MACHINE  TOOLS. 

Notwithstanding  the  vast  amount  of  literature  that  is  being 
circulated  to-day  describing  and  illustrating  the  uses  of  new 
machines,  appliances,  etc. ,  for  economic  manufacturing,  there  is 
a  woful  lack  of  knowledge  among  shop  managers,  superintend- 
ents, and  proprietors  as  to  their  possibilities,  and  among  me- 
chanics of  how  to  operate  them  properly.  If  any  one  has  an  ex- 
cuse for  this  lack  of  knowledge  it  is  the  mechanic ;  for  while  the 
heads  of  establishments  are  constantly  receiving  printed  matter 
describing  what  the  machine  can  do,  and  have  representatives 
calling  on  them  to  discuss  the  labor-saving  features  of  the  ma- 
chines they  are  selling,  the  mechanic  has  to  rely  solely  upon  the 
knowledge  gained  previously  in  the  running  of  other  similar 
machines  to  assist  him  in  mastering  the  details  in  the  operation 
of  the  new  one. 

"UP-TO-THE-MINUTE"   MACHINE  TOOLS 

To-day  the  amount  of  money  and  time  that  is  wasted  every 
day  in  shops  is  apparent  to  very  few.  Even  superintendents, 
shop  managers,  and  master  mechanics  fail  to  realize  the  economy 

512 


INTERCHANGEABLE  MANUFACTURING.  513 

that  can  be  effected  in  the  production  of  duplicate  metal  articles 
and  interchangeable  machine  parts  and  the  increasing  of  the  effi- 
ciency of  the  output,  by  replacing  worn-out  and  obsolete  ma- 
chines with  others  that  are  "up-to-the-minute,"  equipping  them 
with  suitable  fixtures  and  tools,  and  operating  them  as  they  were 
designed  and  built  to  be  operated. 

ADVANTAGES   GAINED   THROUGH   THE   USE   OF 
IMPROVED   TOOLS. 

It  goes  without  saying  that  the  most  important  item  in  the 
cost  of  running  a  modern  machine  shop  or  a  manufacturing  plant 
is  the  labor  bill.  The  tools  and  machines  in  the  hands  of  and 
operated  by  the  workman  determine  the  size  of  the  output  to  a 
given  size  of  labor  account.  Thus  the  advantages  to  be  gained 
in  manufacturing  by  the  use  of  up-to-date  machines  and  special 
tools  and  fixtures  are  obvious;  as  the  cost  of  the  machines  and 
the  amount  expended  in  the  designing  and  constructing  of  special 
tools  will  be  quickly  balanced  on  the  profit  side  when  the  in- 
creased output  and  the  efficiency  of  the  parts  produced  through 
their  use  are  compared  with  the  results  under  the  old  methods. 
Another  advantage  to  be  gained  through  the  use  of  improved 
tools  is  the  almost  total  elimination  of  the  obtainable  results  de- 
pending upon  the  degree  of  skill  and  intelligence  possessed  by 
the  workman ;  thus  allowing  of  employing  less  expensive  help 
in  the  manufacture  of  the  required  parts. 

The  above  enumerated  advantages  gained  through  the  use  of 
modern  machines  and  tools  should  be  so  thoroughly  recognized 
by  the  executive  heads  of  manufacturing  plants  that  the  aim 
should  be  universal  to  weed  out  all  inferior  tools,  and  allow  to 
remain  nothing  but  the  most  efficient  machines,  tools,  and  fixtures 
in  the  bauds  of- the  workman  ;  so  that  the  mechanic  may  produce 
a  greater  quantity,  or  a  better  quality  o^  work,  irrespective  of 
his  degree  of  skill,  and  without  increased  exertion — mentally  or 
physically. 

IDEAL   TWENTIETH-CENTURY   MANUFACTURING. 

Ideal  twentieth- century  manufacturing  is  attained  through 

the  constant  endeavor  of  shop  officials  to  increase  the  dividend 
33 


514  TOOL-MAKING  AND' 

on  each  dollar  of  investment.  If  an  old  machine  can  be  replaced 
with  an  improved  one  which  will  be  capable  of  producing  mure 
work,  or  the  same  quantity  of  work  with  less  labor,  it  should  be 
installed.  Often  the  installation  of  a  new  machine  in  place  of 
an  obsolete  one  has  saved  from  fifteen  to  one  hundred  per  cent, 
and  over  per  annum  on  the  investment.  Those  who  doubt  this 
assertion  have  only  to  inquire  of  the  manufacturers  of  new  ma- 
chines in  order  to  substantiate  my  claim. 

DEPRECIATION   IN   MACHINE-SHOP. 

The  depreciation  of  a  machine-shop  that  is  merely  kept  in 
repair  will  pile  up  just  as  fast  as  better  and  improved  machines 
and  tools  are  installed  and  used  in  competing  shops.  The 
amount  of  depreciation  will  not  be  evidenced  by  the  books ;  but 
it  will  go  on  just  the  same  and  dividends  will  be  declared  out  of 
the  inventory — not  out  of  the  earnings.  Of  course  this  depre- 
ciation can  in  some  cases  be  continued  for  some  years  without 
the  ultimate  end  coming  in  view.  But  at  the  best  the  smash  will 
only  be  postponed  and  the  result  will  be  worse.  Though  this 
simple  decline  in  the  plant's  value  may  not  be  considered  of 
much  moment,  the  increased  cost  of  its  product  and  the  inferior 
efficiency  of  the  same  as  compared  with  that  of  competing  com- 
panies will  eventually  ruin  it.  While  it  is  not  always  possible 
to  replace  all  or  even  the  greater  part  of  an  obsolete  equipment 
with  new  machines,  it  can  be  done  gradually.  Keep  putting  in 
better  and  more  efficient  tools  and  machines  every  year  and  the 
plant  will  keep  its  place  in  the  front  ranks  of  prosperous  establish- 
ments. 

CAUSES   OF   DEPRECIATION   IN   SHOPS. 

Lack  of  concentration,  of  specialization,  of  information,  and 
too  much  attention  to  other  duties  in  the  general  run  of  business 
usually  account  for  the  depreciation  of  a  plant ;  as  the  cost  of 
installing  up-to-date  fixtures  for  the  duplicate  production  of 
small  repetition  parts  and  the  replacing  of  old  machines  with  im- 
proved ones  will  not  ordinarily  exceed  the  extra  cost  per  year  of 
production  by  old  methods  and  of  running  and  keeping  in  repair 
the  old  machines.  In  fact,  there  is  no  excuse  for  the  non-installa- 
tion in  any  shop  of  a  machine  which  will  turn  out  more  and  bet- 


INTERCHANGEABLE  MANUFACTURING.  515 

ter  work  than  an  old  one,  as  the  manufacturers  of  such  machines 
are  always  willing  to  assume  all  cost  of  demonstrating  their  effi- 
ciency and  labor-saving  qualities. 

THE  SELECTION   OE    MACHINES    FOE  MANUFAC- 
TURING   PURPOSES. 

Again,  in  the  selection  of  machines  for  manufacturing  pur- 
poses, extremes  should  be  avoided.  We  have  to  select  from  the 
" universal  type, "  the  " special, "  and  the  "happy  medium. "  The 
"universal "  machine  unsually  lacks  efficiency ;  and  it  is  difficult 
to  produce  interchangeable  machine  parts  of  a  high  grade  in  it. 
The  " special "  machine  lacks  working  range;  and  unless  large 
quantities  of  work  of  the  same  kind  are  constantly  required  the 
machine  is  frequently  idle.  The  "happy  medium,"  then,  is  the 
one  for  most  shops. 

UNIVERSAL   EQUIPMENT   VS.    WORKING-RANGE 
EQUIPMENT. 

In  the  average  machine-shop  or  manufacturing  plant  of  to- 
day important  changes  frequently  occur.  In  such  establishments 
the  efficiency  of  the  manager  lies  in  his  ability  to  have  the  shop 
ready  for  such  changes — changes  which  frequently  entail  the 
entire  product  of  the  works.  Thus  a  well-informed  and  prac- 
tical manager  is  able  to  make  changes  in  the  product  and  at  the 
same  time  avoid  an  excessive  depreciation  of  the  shop's  value. 

The  properly  equipped  machine-shop  of  to-day  has  an  equip- 
ment which  is  either  universal  or  at  least  within  its  working 
range  and  which  will  at  the  same  time  possess  the  greatest  effi- 
ciency. Thus  the  jobbing  shop  will  have  a  universal  equipment ; 
while  the  machine-tool  shop  will  have  a  working-range  equip- 
ment. It  is  to  such  plants  that  we  owe  our  manufacturing 
supremacy,  as  they  are  the  ones  who  compete  with  and  under- 
sell foreign  manufacturers  on  their  own  ground. 

CAUSE  OF  THE  GREAT  DEVELOPMENT  IN  MACHINE 

TOOLS. 

The  introducing  of  innovations  and  the  adaptation  of  radical 
ideas  are  constantly  occurring  all  along  the  lines  of  machine-tool 
manufacturing  and  the   production   of  mechanical   apparatus. 


516  TOOL-MAKING. 

The  cause  of  this  wonderful  growth  in  the  number  of  types  of 
machine  tools,  and  their  great  capacity  for  fine  work,  may  be 
directly  traced  to  the  great  improvements  in  electrical  devices, 
necessitating  numbers  of  machine  tools  of  improved  construction 
to  produce  their  complicated  parts.  This  has  been  the  cause  of 
the  great  activity  in  machine-tool  improvement  and  building  be- 
cause, first,  it  called  for  new  methods  and  facilities  for  manu- 
facture. 

Another  event  having  an  effect  on  the  designing  and  manu- 
facturing of  machinery  entirely  unlooked  for  at  the  time  of  its 
inception  was  the  manufacture  of  the  bicycle.  This  event 
brought  out  the  capabilities  of  the  American  mechanic  as  noth- 
ing else  had  ever  done.  It  demonstrated  to  the  world  at  large 
that  he  and  his  kind  were  capable  of  designing  and  making 
special  machinery,  tools,  fixtures,  and  devices  for  economic  man- 
ufacturing in  a  manner  truly  marvellous ;  and  has  led  to  the  in- 
stallation of  the  interchangeable  system  of  manufacture  in  a 
thousand  and  one  shops  where  it  was  formerly  thought  to  be 
impracticable. 

The  autocar,  automobile,  and  autocycle  are  the  latest  creations 
to  demand  the  attention  of  the  designer,  tool-maker,  and  the  ma- 
chinist. It  is  in  the  perfecting  and  manufacturing  of  these 
twentieth -century  marvels  of  mechanism  that  they  are  showing 
the  world  that  to  them  nothing  is  impossible,  and  that  the  in- 
genuity and  skill  which  perfected  the  "dollar  watch"  will  also 
prove  adecpiate  to  produce  an  "automobile  for  the  million." 
Forward  ! 


INDEX. 


Abrasive,  aluminum  as  an,  500 
Accurate  jig-making,  processes  of,  43 

jigs,  36 

work,  milling  fixtures  for,  141 

work  on  dies,  special  machines  for,  355 
Acetylene  gas  burners,  drill  jig  for,  68 
Action  of  sub-press  dies,  466 
Advantage  gained  through  the  use  of  improved  tools,  513 

in  the  use  of  special  tools,  223 

of  the  end  cut  in  boring  tools,  248 
Aligning  cutter-grinder  centres  with  micrometer,  272 

lathe  centres  with  micrometer,  271 
Allis-Cbalmers  Company,  production  of  perforated  metal  by,  439 
Aluminum,  annealing,  497 

as  an  abrasive,  500 

base  casting,  drill  jig  for,  92 

bending  and  forming  dies  for,  496 

burnishing,  498 

cutting  dies  for,  495 

difficulties  encountered  when  working,  492 

drawing  dies  for,  495 

engraving  and  chasing,  498 

grades  and  alloys  of,  493 

lubricating  when  working,  494 

polishing  and  finishing,  497 

processes  and  methods  for  working,  492 

pure  metal  vs.  alloys  of,  492 

secrets  in  working,  493 

sheets,  necessary  to  lubricate  before  working,  413 

shell,  die  for  blanking  and  drawing,  embossing,  410 

shells,  blanking  and  drawing,  413 
drawing,  496 

soldering,  499 

spinning,  496 

working  the  metal,  493 
American  Machinist,  extracts  from  articles  in,  121-251 
American  mechanic,  capabilities  of,  516 

tool-maker,  26 

517 


518  INDEX. 

Angle  plate,  milling  one,  125 
Annealing  aluminum,  497 

and  lubricating  shells  in  drawing,  868 
Armature  disks,  453 

machines  and  dies  for,  454 
of  large  diameters,  454 
piercing  and  perforating,  437 
segment  blanks,  460 

notching  press,  460 
segments,  459 
what  constitutes,  454 
Art  goods,  dies  for  stamping  and  embossing,  468-478 
of  sheet-metal  working  in  dies,  365 
of  swaging,  477 
Assortment  of  milling  cutters,  picking,  232 
Attachment  for  cylindrical  perforating,  433 

for  drilling  and  tapping  in  the  turret-lathe,  183 
for  forming  pieces  from  bar  in  turret-lathe,  163 
Automobiles  for  the  million,  516 

B 

Bag  clasps,  dies  for  sheet-metal,  403 
Bath  for  cutters,  hot  lead,  241 
Bearing  bracket,  drill  jig  for,  62 

milling  fixture  for,  131 
Bending  and  forming  dies  for  aluminum,  496 

nice  job  in,  416 
Bicycle  handle-tips,  moulds  for  making,  293 
Blades,  holding  milling-cutter,  229 
Blanking  dies,  cheap,  372 
Blanks,  fining  for  drawn  shells  and  cups,  369 
Boring  bars  and  reamers,  224 

brackets  and  spindle  heads,  special  machines  for,  214 

drill  jig  for  power-press  bolster,  102 

drill-press  tables,  220 

fixtures,  drill-press  and,  208 

long  cast-iron  cylinders,  509 

rig  for  drill-press,  212 
Bottomless  shells,  perforating  small  close  patterns  in,  435 
Bottoms,  double  seaming  of  round,  441 

seaming  burred-edged,  441 
Box  lid  fastening  plates,  dies  for,  389 

straps,  piercing  and  spreading  dies  for,  385 

tool  for  turret-lathe,  169 

tools  for  screw  machine,  four  special,  190 
Bracket,  bearing,  drill  jig  for,  62 

milling  fixture  for,  131 
Brass,  bronze,  and  copper  dies,  477 

clock  wheels,  punching,  376 


INDEX.  519 


Brass  parts,  reaming  holes  in,  258 

rings,  making  thin,  305 

working  tools,  and  bow  to  use  them,  503 
Broaches  and  broaching,  260 

some  points  about,  265 
Broaching,  interesting  job  of,  262 

its  relation  to  sheet-metal  work,  267 

operation  of,  261 
Bronze,  brass,  and  copper  dies,  477 
Brown  and  Sharpe  tool-rooms,  39 
Burner  shells,  perforating,  434 
Burning  cutters,  237 
Burnishing  aluminum,  498 
Burred-edged  bottoms,  seaming  them,  441 
Bushing  holes,  button  method  for  locating,  43 
locating  and  finishing  in  large  jigs,  48 
Button  method  for  locating  drill  bushing  holes,  43 

C 
Cam  body,  drill  jig  for  multiple,  81 

milling  machine,  special,  337 

set  of  tools  for  machining,  300 
Cams,  drill  jig  for,  78 

indexing  dial  jig  for,  109 
Casting  to  be  jigged,  patterns  for,  47 
Cast  iron  impression  cylinder,  drill  jig  for,  98 
tank  for  pickling,  509 
tinning,  509 
Cause  of  great  development  in  machine  tools,  515 
Causes  of  depreciation  in  machine  shops,  514 
Centre  reamers,  257 

Chasing  designs  in  mountings  of  metal,  472 
Cheap  blanking  dies,  372 

jigs,  35 
Chief  factors  in  machine  manufacturing,  160 
Chucks  for  eccentric  straps,  340 

for  gasoline  engine  cylinders,  342 

for  holding  pulleys  in  the  turret  lathe,  170-172 

for  turning  eccentric  rings,  338 

two  eccentric  cams,  two-nose,  341 
Circular  forming  tools,  253 
notes  on,  501 

shearing  machines,  456 

shells,  large  drawing  dies  for,  391 
Clamp  for  die  and  tool-makers'  use,  509 
Cloth,  hollow  cutters  for  punching,  297 
Coins,  dies  for,  468-469 
Cold  swaging  process,  479-482 
Collet  spring  chucks,  310 


520  INDEX. 

Combination  dies  for  embossed  work,  475 

Compound  dies  for  parts  of  telephone  transmitter  cases,  423 

Constructing  simple  drill  jigs,  43 

special,  devising  and,  300 
Construction  and  design  of  novel  drill  jigs,  106 

of  milling  machines,  improvements  in,  122 
Copper,  bronze,  and  brass  dies,  477 
Corkscrews,  machine  for  twisting,  3*27 
Cost  vs.  longevity  of  the  sub-press,  463 
Counterbores,  254 
Counterboring,  254 

large  casting  in  drill-press,  facing  and,  352 
Cup  centres,  finishing,  222 
Curling  and  wiring  processes,  447 

deep  shells,  452 

punch  and  die,  452 

the  edges  of  circular  shells,  447 
of  drawn  shells,  450 
Cut-off  and  forming  tool,  hand  for  the  speed-lathe,  315 
Cutters,  assortment  of  milling,  232 

burning,  237 

classified,  milling,  224 

degree  of  hardness  in,  241 

end  mill,  227 

gang  milling,  235 

hardening,  239 

and  tempering,  239 

heating,  240 

and  hardening  large,  243 

holding  inserted  blades  of  milling,  229 

injury  in  hardening,  241 

inserted  teeth,  228 

interlocking,  235 

lead  bath  for,  241 

limits  of  inaccuracy  in,  229 

making  milling,  235 

plunging,  241 

regrinding  of,  231 

sand-blasting,  242 

selecting  a  set  of,  232 

shell  and  end  milling,  234 

side  clearance  in,  228 

speeds  and  feeds  of,  236 

spindle  surface,  milling,  234 

standard  styles  and  sizes  of,  226 

steel  for,  quality  of,  231 

suggestions  for  milling  with,  238 

test  for  hardness  in,  242 

undercut  teeth,  226 


INDEX.  521 


Cutters,  use  and  abuse  of  milling,  230 

warping,  241 
Cutting  dies  for  aluminum,  495 

edges  desirable  for  boring  tools,  number  of,  246 

leather,  cloth,  and  paper  with  dinking  cutters,  397 

soft-rubber  articles,  506 
Cylinders,  boring  cast-iron,  509 
Cylindrical  perforating,  attachment  for,  433 

D 
Dayton  swaging  machine,  485 
Decorated-sheet  metal  articles,  drawing,  369 
Deep  hole  drilling,  244 

shells  from  sheet  metal,  drawing,  393 
Deflecting  device  for  seaming  machines,  443 
Degree  of  hardness  in  cutters,  241 
Depreciation  in  machine-shops,  514 

in  shops,  causes  of,  514 
Depth  to  which  shells  may  be  drawn,  368 
Design  and  manufacture  of  milling  cutters,  226 
Designer,  the,  29 
Device  for  turret-lathe,  190 

Devising  and  constructing  special  tools,  ability  to,  300 
Dies,  and  tool-makers'  clamp,  509 
art  goods,  468-478 
bending  and  drawing,  496 
brass,  477 

clock  gears,  376 
bronze,  477 
cheap  blanking,  372 
coining,  468-470 

compound,  for  telephone  transmitter  cases,  423 
copper,  477 
curling,  452 

cutting,  for  aluminum,  495 
drawing  for  aluminum,  495 

for  large  shells,  391 
engraving,  468-478 
filing  machine  for,  361 
for  box -corner  fasteners,  383 
bending  and  forming,  416 
blanking  and  drawing  aluminum  shells,  413 
embossing  jewelry,  making,  469 
forming  large  sheet-metal  articles,  474 
jewelry,  468-478 
sheet-metal  bag  clasps,  403 
gang  sets  for  eyelets  in  one  operation,  420 
hand-finishing  vs.  machine-finishing  of,  356 
bobbing,  468-478 


522  IXDEX. 

Dies,  improved  piercing,  388 
machine  for  filing,  358 
making  hobs  and  sinking  embossing,  476 
making  kink  for,  314 
milling  machines,  use  of,  357 
patterns,  modelling  intricate,  472 
piercing  and  spreading,  385 
punching  and  curling,  399 
without  waste  in,  380 
simper  for,  358 
shearing,  373 
sinking  attachment  for,  358 

with  hobs,  468-478 
slotter,  small,  360 
small  hole  finishing,  374 
special  machines  for  accurate  work  on,  355 
sub-press,  action  of,  466 
triple-acting,  410 
water  or  fluid,  474 
Difficulties  encountered  in  working  aluminum,  492 
Disks,  armature,  piercing  and  perforating,  437 
cutting  armature,  453 
of  large  diameters,  454 
Double  horning  and  seaming,  443 

seaming  bottoms  on  heavy  work,  447 
machine  for  irregular  articles,  445 
of  bottoms  on  special  work,  447 
irregular  can  bottoms,  443 
round  can  bottoms,  441 
Doubt  as  to  the  utility  of  milling  machines,  128 
Drawing  aluminum  shells,  496 

and  forming  decorated  sheet-metal  articles,  369 
annealing  and  lubricating  shells  in,  368 
a  sharp  corner  under  a  shoulder,  502 
deep  shells  from  sheet  metal,  393 
dies,  for  aluminum,  495 

way  to  construct,  370 
shell  from  thin  metal,  lubricant  for,  510 
Drawn  shells,  finding  the  blanks  for,  369 

work  processes  for,  367 
Drill  bushing  holes  in  large  jigs,  locating,  48 
button  method  for  locating,  43 
notes,  252 

press  and  boring  fixtures,  208 
boring  rig,  212 
cup  centres,  finishing,  222 

facing  and  counterboring  large  castings  in,  352 
flat  tables,  boring,  220 
job,  a,  306 


INDEX.  523 


Drill-press,  milling  in  the,  311 

round  tables,  machining,  222 
Drilling  and  tapping  attachment  for  turret  lathe,  183 
deep  holes  by  Pratt  and  Whitney  method,  249 
holes  in  helical  surface,  313 
jigs,  constructing  large,  96 
simple,  43 
for  acetylene  gas-burners,  68 

an  aluminum  base  casting,  92 
a  spiral  line  of  holes  around  a  cjdinder,  106 
bearing  bracket,  62 
cams,  78 

cast-iron  impression  rollers,  98 
dovetailed  slide  bracket,  101 
drilling  and  countersinking,  76 
drilling  and  hobfacing,  83 
drilling  and  tapping,  115 
multiple  cam  body,  81 
nailing-machine  cross-head,  96 
odd-shaped  casings,  70 
power-press  bolster,  102 
round  castings  in  pairs,  74 
small  accurate  work,  89 
spider  castings,  115 
the  speed  lathe,  66 
typewriter  bases,  85 
indexing  dial  for  small  cams,  109 
intricate  and  positive,  81 
novel,  118 

design  and  construction,  106 
points  to  remember  when  making,  104 
simple,  42 

fourteen-hole,  59 
special  milling  and,  354 
their  use,  simple,  64 
with  indexing  fixtures,  109;  111,  114 
job  on  the  planer,  308 
set  of  milling  and,  348 
small  thread  dies,  jig  for,  325 
types  of  simple  jigs,  55 
Duplicate  work  in  screw  machine,  method  for  finishing,  195 

E 

Eccentric  cams,  two-nose  chucks  for  machining,  341 

rings,  chucks  for  turning,  338 

straps,  chuck  for  machining,  340 
Effects  of  work  accomplished  by  swaging,  491 
Eli  Whitney,  19 


524  INDEX. 

Embossed  work,  combination  dies  for,  474 
Embossing,  blanking,  and  drawing,  410 

jewelry,  making  dies  for,  469 
End  cut  in  boring  tools,  advantage  of,  248 
Engraving  a  hob  for  sinking  medal  dies,  468 

and  chasing  aluminum,  498 

dies  for  embossing  jewelry,  468-470 

machine,  special,  334 
Etching  steel,  how  to  do  it,  509 
Examples  of  special  uses  of  height-gauge,  274-278 

of  micrometer,  271 
Expansion  reamers,  258 
Eyelets,  gang  punch  and  die  for,  420 


Pace  milling,  fixtures  for,  139 

Facing  and  counterboring  large  castings  in  drill-press,  352 

tools,  254 
Factors  in  machine  manufacturing,  160 

in  the  successful  use  of  milling  fixtures,  141 

involved  in  designing  of  drill  jigs,  40 
Feeding  sheet  metal  to  the  sub-press,  466 
Feeds  and  speeds  for  milling  cutters,  236 
Fibre  washers,  special  tool  for  cutting  out,  329 
Filing  dies,  machines  for,  358 

machine,  361 
Finding  the  blanks  for  drawn  shells,  369 
Finishing  cup  centres  of  drill-presses,  222 

of  dies,  hand  vs.  machine,  356 
Fixtures  for  adjustable  stops  and  spindle  racks,  jigs  and,  320 

for  milling  drill-press  tables,  152 
Flaking  stick,  its  use,  311 
Flat  jigs,  their  use,  32 
Follow  dies,  gang  and,  366 
Forming  irregular  pieces  from  the  bar,  fixture  for,  163 

pieces  of  irregular  outline,  fixture  for,  200 

tools,  notes  on  circular,  501 
Four  special  box  tools  for  the  screw  machine,  190 
Fourteen-hole  drill  jig,  59 

'      G 
Gang  and  follow  dies,  366 

die  for  metal  box-lid  fastening  plates,  389 
milling  cutters,  235 
fixtures  for,  138 
punch  and  die  for  producing  eyelets  in  one  operation,  420 
Gasoline  engine  cylinders,  chuck  for  machining,  342 
Gauges,  32 
Gears,  speeds  of  pulleys  and,  508 


INDEX.  525 


Gelatin  moulds,  making,  472 

Glue  for  leather  and  iron,  510 

Grades  and  alloys  of  aluminum,  493 

Great  development  in  machine  tools,  causes  of,  515 

Grinder,  aligning  cutter,  centres,  272 

Grinding  of  cutters,  239 

rubber,  506 

twist  drill  for  cutting  section  of  hole,  505 
Grit  in  rubber,  505 

H 

Hammering  and  swaging,  479 

Hand  cut-off  and  forming  tool  for  speed  lathe,  315 

finishing  vs.  machine  finishing  of  dies,  356 

reaming,  259 
Hardening  and  tempering  of  milling  cutters,  239 

injury  in  cutters,  241 

test  for,  242 
Hardness,  degree  of,  in  cutters,  241 
Hard-soldering,  507 
Heating  and  hardening  large  cutters,  243 

the  steel,  240 
Heavy  work,  jigs  for,  34 
Height-gauge  and  its  use,  274 

examples  of  use  of,  274-278 
locating  holes  with,  275 
shop  use  of,  268 
Holding  cutter  blades,  229 

devices  for  jigs,  locating  and,  41 
Hollow  cutters  for  punching  leather,  cloth,  and  paper,  397 

drill,  boring  spindles  with,  251 
Home-made  reamers,  259 
Horizontal  swaging  machines,  489 
Horning  and  seaming  processes,  440 

double  seaming  and,  443 

How  to  construct  a  sub-press,  463 

drawing  dies,  370 

I 

Ideal  twentieth-century  manufacturing,  513 
Improved  piercing  die,  388 

tools,  advantages  gained  through  the  use  of,  513 
Improvement  in  construction  of  milling  machine,  122 
Increasing  the  size  of  worn  reamers,  260 
Indexing  dial  jig  for  small  cams,  109 

milling  fixtures,  147 

plates,  jigs  with,  109,  111,  114 
Injury  in  hardening  cutters,  241 
Inserted  teeth,  holding,  229 
cutters,  228 


526  INDEX. 

Inside  blank -holders,  392 

Installation  of  armature  disk  punching  machinery,  458 

of  the  interchangeable  system,  23 
Interchangeability,  20 

Interchangeable  manufacturing,  milling  machines  and,  120 
origin  of,  19 
to-day,  22 
Interesting  job  of  broaching,  262 
Interlocking  cutters,  235 
Intricate  and  positive  drill  jigs,  81 

machinery,  modern  manufacturing  of,  23 
Irregular  articles,  double  seaming  machine  for,  445 
Iron  and  leather,  glue  for,  510 

J 

Jeweliiy,  dies  for  making,  468-478 

making  dies  for  embossing,  469 
Jigs  and  fixtures,  functions  of,  30 

bodies,  handling  large,  52 

box,  33 

cheap,  35 

design,,  factors  involved  in,  40 

feet,  53 

flat,  32 

large,  48 

making,  processes  for  accurate,  43 

work  on  the  plain  miller,  50 
Jobbing  shop  work,  milling  machines  and,  120 

K 
Keeping  note-books,  511 

sheets  straight  while  perforating,  438 
Keyseating  in  the  power-press,  315 
Kink,  die-making,  314 
Knee  type  of  universal  milling  machines,  123 


Lack  of  knowledge  of  machine  tools,  512 
Large  drawing  dies  for  circular  shells,  391 

drilling  jigs,  48 
Lathe  chuck,  simple,  312 

tool-maker's,  36 
Leather  and  iron,  glue  for,  510 

hollow  cutters  for  punching,  397 
Limits  of  inaccuracy  in  milling  cutters,  229 
Locating  and  finishing  drill  bushing  holes  in  large  jigs,  48 

and  holding  devices  for  drill  jigs,  41 

drill  bushing  holes,  button  method  for,  43 
Lock  seam,  successive  stages  of,  441 


INDEX.  527 

Lubricants  to  use  for  drawing  shells  from  thin  metal,  510 

for  working  aluminum,  494 
Lubricating  and  annealing  shells  for  drawing,  368 

M 
Machine,  Dayton  swaging,  487 

die  filing,  361 

finishing  vs.  hand  finishing  of  dies,  356 

for  double-seaming  irregular  bottoms,  445 

for  engraving  poker  chips,  334 

for  filing  dies,  358 

for  twisting  corkscrews,  327 

manufacturing,  chief  factor  in,  160 

reaming  of  brass  parts,  258 
with  floating  reamer,  255 

shops,  cause  of  great  depreciation  in,  514 

special  cam  milling,  337 
engraving,  334 

tools,  28 

cause  of  the  great  development  in,  515 
lack  of  knowledge  of,  512 
up-to-the-minute,  512 
Machinery,  extracts  from  articles  in,  244-481 
Machinery  for  double-seaming  round  bottoms  on  cans,  442 
Machines  and  dies  used  for  perforating  armature  disks,  454 

horizontal  swaging,  489 

rotary  swaging,  485 

special,  for  accurate  work  on  dies,  355 
Machining  a  cam,  special  tools  for,  300 

a  special  casting,  tools  for,  180 

drill  columns,  156 

pulleys,  detail  drawings  of  special  tools  for,  172 

round  tables,  220 
Making  and  use  of  simple  dies,  371 

dies  for  embossing  jewelry,  469 

hobs  and  sinking  embossing  dies,  476 

impressions  of  elaborate  dies,  473 

thin  threaded  brass  rings,  305 

drill  press  cup  centres,  222 

collet  spring  chucks,  310 
Manufacture  of  accurate  sheet-metal  parts  in  the  sub-press,  461 

of  armature  disks  and  segments,  453 
segments,  large,  459 

of  milling  cutters,  design  and,  224 
Manufacturing,  chief  factor  in  machine,  160 

ideal  twentieth-century,  513 

of  intricate  machinery,  23 

origin  of  interchangeable,  19 

purposes,  selection  of  machines  for,  515 


528  INDEX. 

Manufacturing,  to-day,  ideal  interchangeable,  22 
Medal  dies,  engraving  a  steel  hob  for  sinking,  468 
Metal  box -corner  fasteners,  dies  for,  383 

patterns,  23 
Method  for  finishing  duplicate  work  in  the  screw  machine,  195 

for  locating  drill  jib  bushings,  button,  43 
Micrometer  calipers,  268 
reading  them,  270 
special  uses  for,  271 

aligning  cutter  grinder  centres  with,  272 

lathe  centres,  testing  for  height  of,  with,  272 

testing  lathe  centres  for  alignment,  271 

universal  use  of,  274 

used  as  inside  calipers,  273 
Milling  and  drilling  jigs,  set  of  special,  348 
Milling-cutters,  assortment  of,  232 

burning,  237 

classified,  224 

degree  of  hardness  in,  241 

end,  227 

face,  139 

gang,  138-235 

hardening  and  tempering,  239 

heating,  240 

heating  and  hardening  large,  243 

holding  blades  in,  229 

injury  in  hardening,  241 

inserted  teeth,  228 

interlocking,  235 

lead  bath  for  heating,  241 

limits  of  inaccuracy  in,  229 

making,  235 

miscellaneous,  152 

plunging  when  hardening,  241 

quality  of  steel  to  use  for,  231 

regrinding  of,  231 

sand-blasting  of,  242 

selecting  a  set  of,  232 

shell  and  end,  234 

side  clearance  on,  228 

speeds  and  feeds  for,  236 

spindle  surface,  235 

standard  types  and  sizes  of,  226 

test  of  hardness  of,  242 

undercut  teeth,  226 

use  and  abuse  of,  230 

warping  in  hardening,  241 
Milling-fixtures,  factors  in  the  successful  use  of,  141 

for  accurate  work,  141 


INDEX.  520 

Milling-fixtures  for  bearing  bracket,  131 

for  drill-press  tables,  152 

for  slotting  and  dovetailing  small  pieces,  134 

for  squaring  ends  of  duplicate  pieces,  132 

indexing,  147 

simple,  129 

six  simple  and  distinct  types  of,  129 
iMilliug-macliines,  compared  with  other  machine  tools,  124 

doubt  as  to  the  utility  of,  128 

improvements  in  construction  of,  122 

in  the  drill  press,  311 

in  the  tool-room,  125 

knee  type  of  universal,  133 

modern  tool-making  and,  120 

practice,  most  vital  point  in,  236 

spindle  racks,  milling  in,  323 

universal  types  of,  122 

use  of  die,  357 

of  universal  and  plain,  120 

utility  of,  120 

vertical  spindle,  127 
Modeller's  wax,  making  and  using,  473 
Modelling  intricate  die  patterns,  472 
Most  skilled  mechanic  in  the  world,  26 
Moulds,  279 

construction  of,  279-299 

for  bicycle  handle-tips,  293 

for  lead  balls,  282 

for  pencil  crayons,  279 

for  poker-chips,  296 

for  spherical  articles,  298 

for  telephone  receiver  pieces,  285 

gelatin,  for  fancy  die  work,  472 

how  an  accurate  set  of,  was  machined  in  the  planer,  288 
Movable  strippers,  379 
Multiple  cam  body,  drill  jig  for,  81 
Multi -spindle  drilling  and  tapping  attachment  for  turret-lathe,  183 

N 

Necessity  to  lubricate  aluminum  before  working,  413 
IS'ice  job  of  bending  and  forming,  416 
Note-books,  how  to  keep  them,  511 
Notes  on  circular  forming  tools,  501 

on  drills,  252 
Novel  drill  jigs,  106-118 

O 

Oberlin  Smith's  "Press  Working  of  Metals,"  267 
Operation  of  broaching,  261 
34 


530  INDEX. 

Origin  of  interchangeable  system,  19 
Ornamental  articles,  dies  for  forming,  472 


Paper,  hollow  cutters  for  punching,  397 

Patent  tool-holders,  507 

Patterns  for  castings  to  be  jigged,  47 

Pencil  crayons,  set  of  moulds  for,  279 

Perforated  metal,  production  of,  by  Allis-Chalmers  Company,  439 

Perforating  and  blanking  small  armature  disks,  437 

and  piercing,  367 

attachments  for  cylindrical,  433 

burner  shells,  434 

flat  and  cylindrical  sheet-metal  articles,  433 

keeping  sheets  straight  while,  438 

large  sheets  of  metal  in  special  designs,  438 

small  close  patterns,  435 

taper  and  crowning  shells,  434 
Petroleum  cans,  seaming  them,  445 
Pickling  cast  iron,  tanks  for,  500 
Piercing  and  perforating,  367 

and  spreading  die  for  box  straps,  385 

die,  improved,  388 
Plain  forming  tools,  253 

miller,  jig  work  in,  50 
Planer,  accurate  set  of  moulds  machined  in,  288 
Plunging  heated  cutters,  241 
Points  about  broaches  and  broaching,  265 
Poker-chips,  set  of  moulds  for,  296 
Polishing  and  finishing  aluminum,  497 
Polyphase  motor,  456 
Positive  drill  jigs,  intricate  and,  81 
Power-press,  key-seating  in,  315 

bolster,  drill  jig  for,  102 
Power-presses  used  for  disk  punching,  457 
Pratt  and  Whitney  method  of  deep  hole  drilling,  249 
Press,  armature  disk  notching,  460 

tools,  simplest  clas<:  of,  366 

work,  432 
"Press  Working  of  Metals,"  Oberlin  Smith's,  267 
Principal  use  of  sub-press,  462 
Principle  of  reproduction,  great,  29 
Process,  cold  swaging,  482 
Processes  and  methods  for  working  aluminum,  492 

for  curling  and  wiring,  447 

for  drawn  work,  367 

horning  and  seaming,  440 

of  accurate  jig  making,  43 


INDEX.  531 


Producing  parts  without  waste,  die  for,  380 
Progress  made  in  the  use  of  power-presses,  355 
Projectiles,  reamers  for,  257 
Pulleys  and  gears,  speeds  of,  508 

set  of  tools  for  machining  in  one  operation,  172 
Punching  and  curling  job,  399 

brass  clock  gears,  376 
Pure  metal  vs.  alloys  of  aluminum,  492 

Q 

Quality  of  steel  to  use  for  cutters,  231 

R 

Razors,  aluminum  for  sharpening  or  honing,  500 
Reading  micrometers,  270 
Reamers  and  reaming,  255 

centre,  257 

expansion,  258 

for  babbit  metal,  257 

for  projectiles,  257 

hand,  259 

home  made,  259 

increasing  the  size  of,  when  worn,  260 

small  parts,  machine,  258 
holes,  259 

square,  258 

taper  of  rose,  257 
Reaming  holes  in  the  screw  machine,  taper,  256 
in  the  turret-lathe,  255 
in  thin  disks,  255 
in  two  kinds  of  metals,  257 
taper  holes  in  cast  iron,  256 
with  the  floating  reamer,  255 
Receiver  pieces,  moulds  for  telephone,  285 
Regrinding  of  milling  cutters,  231 
Relation  of  broaching  to  sheet-metal  work,  267 
Reproduction,  the  great  principle  of,  29 
Rolling  of  seams,  446 
Rose  reamers,  taper  of,  257 
Rotary  swaging  machines,  485 
Rough  castings  in  pairs,  drilling,  74 
Round  bodies,  machine  for  double-seaming,  442 

drill  tables,  machining,  222 
Rubber,  cutting  soft,  506 

grinding,  506 

turning  and  truing,  505 


532  INDEX. 

S 

Sand-blasting  of  milling  cutters,  242 
Screw,  cutting  coarse-pitch,  804 

machine,  method  for  finishing  duplicate  work  in,  195 

special  tools  for,  190 

tools  and  fixtures  for  speed  indicators,  193 
Seaming  bottoms  with  burred  edges,  441 

double  horning  and,  443 

horning  process  and,  440 

petroleum  cans,  445 
Secrets  of  working  aluminum,  493 
Selecting  a  set  of  milling  cutters,  239 
Set  of  jigs  for  milling  and  drilling,  348 

of  tools  for  machining  a  cam,  300 
Sextet  casting,  boring  and  facing  fixture  for,  209 
Shearing  die,  373 
Sheet  brass  blanks,  trimming,  313 

Sheet  metal,  depth  which  may  be  drawn  at  one  operation,  368 
drawing  deep  shells  from,  393 
parts,  drawing  and  forming  decorated,  369 
use  of,  in  place  of  other  materials,  365 
work,  broaching,  its  relation  to,  267 
Shell  and  end  milling  cutters,  234 

bottomless,  perforating,  435 

burner,  perforating,  434 

cylindrical,  perforating,  433 
Side  clearance  in  milling  cutters,  228 
Simple  dies,  making  and  use  of,  371 

drill  jigs,  42 

constructing,  43 

drilling  jigs  and  their  use,  64 
fourteen-hole,  59 
types  of,  55 

lathe  chuck,  312 

milling  fixtures,  129 

six  distinct  types  of,  129 

slotting  fixture,  314 
Simplest  class  of  press  tools,  366 
Sinking  embossing  dies  and  drop  dies,  468-478 
Slotter,  small  die,  360 

Slotting  and  dovetailing  small  castings,  milling  fixture  for,  134 
Small  accurate  work,  drill  jig  for,  89 

cams,  indexing  dial  jig  for,  109 

thread  dies,  jig  for  drilling,  325 
Smith,  Oberlin,  267 
Soldering  aluminum,  499 

face  plate,  a,  310 

hard-,  507 


INDEX.  533 


Some  points  about  broaches  and  broaching,  265 
Special  box  tools  for  screw  machine,  190 
cam  milliug  machine,  337 
casting,  tools  for  machining,  180 
chucks  for  turret-lathe,  170 
designs,  perforating  large  sheets  in,  439 
engraving  machine,  334 
fixtures  in  the  turret-lathe,  use  of,  162 
job  of  tool-making,  331 
machine  for  accurate  work  on  dies,  355 

for  boring  drill-press  brackets  and  spindle  heads,  214 
milling  and  drilling  jigs,  344 
tools,  advantage  in  the  use  of,  223 

and  fixtures  for  machining  pulleys,  172 
for  cutting  out  large  fibre  washers,  329 
for  the  sc-ew  machine,  190 
for  turret-lathe,  162 
uses  of  micrometer  calipers,  271 
Speed  and  feed  of  milling  cutters,  239 
indicators,  tools  and  fixtures  for,  190 
lathe  milling,  jig  for,  318 
of  pulleys  and  gears,  508 
Spherical  moulds,  298 
Spindle  racks,  milling,  322 

fixture  for,  320 
Spring  strippers,  379 

winding  fixture,  309 
Square  reamers,  258 
Squaring  holes,  die  for,  374 

the  ends  of  duplicate  pieces,  milling  fixture  for,  132 
Standard  types  of  milling  cutters,  226 
Stationary  strippers  sometimes  distort  sheets,  379 
Step  jig,  307 
Stick,  flaking,  311 

Straps,  cam  for  turning  eccentric,  340 
Sub-press,  461 

cost  vs.  longevity  of,  463 
dies,  action  of,  466 
feeding  the  metal  to,  466 
how  to  construct,  463 
setting  and  using,  465 
use  of,  462 
utility  of,  462 
Successful  use  of  milling  fixtures,  factors  in,  141 
Swaging,  cold,  processes  of,  479 

effects  of  work  accomplished  by,  491 
machines,  horizontal,  489 
rotary,  485 
the  Dayton,  487 


534  INDEX. 

T 
Tanks  for  pickling  cast  iron,  509 
Taper  and  crowning  shells,  perforating,  434 

of  rose  reamers,  257 

reaming  in  the  screw  machine,  256 
Telephone  receiver  pieces,  moulds  for,  285 

transmitter  cases,  compound  dies  for,  423 
Templets,  31 

Test  for  hardness  of  cutters,  242 

Testing  lathe  centres  for  height  with  micrometer  calipers,  272 
The  hammer,  479 

height-gauge  and  its  use,  274 

most  skilled  mechanic  in  the  world,  26 
Tinning  cast  iron,  509 
Tool-holders,  patent,  507 
Tool-maker's  lathe,  36-37 
Tool-making,  milling  machine  and  modern,  120 

unusual  job  of,  331 
Tool-rooms,  and  their  equipment,  36 

Brown  and  Sharpe,  39 

milling  machines  in,  125 
Tools  for  screw  machine,  special,  190 

for  speed  indicators,  screw  machine,  193 
Trimming  sheet-metal  blanks,  313 

Triple-action  die  for  blanking,  drawing,  and  embossing,  410 
Turret-lathe,  attachment  for  forming  irregular  pieces  from  the  bar,  163 

box  tool  for,  160 

multi-spindle  drilling  and  tapping  fixture  for,  183 

set  of  tools  for  machining  pulleys  in,  172 

special  tools  for,  162 

tools  for  machining  a  special  casting  in,  180 

two  special  chucks  for,  170 

use  of  special  device  for,  190 
special  fixtures  in,  162 
Twentieth-century  manufacturing,  ideal,  513 
Twist-drill,  245 

grinding  for  cutting  section  of  hole,  505 
Twisting  corkscrews,  327 
Two-nose  chucks  for  eccentric  cams,  340 
Types  of  very  simple  milling  fixtures,  six  distinct,  129 

very  simple  drilling  jigs,  55 
Typewriter  bases,  drill  jig  for,  85 

U 

Undercut  teeth,  milling  cutters  with,  226 

Universal  equipment  vs.  working-range  equipment,  515 

milling  machines,  122 
Up-to-date  fixtures  and  machine  tools,  512 


INDEX.  535 


Up-to-the-minute  machines  and  tools,  512 
Use  and  abuse  of  milling  cutters,  230 

and  construction  of  boring  fixtures,  208 

of  brass-working  tools,  503 

of  modeller's  wax,  making  and,  473 

of  micrometer  calipers,  268 

of  milling  fixtures,  factor  in  the  successful,  141 

machines,  120 
of  power-presses,  progress  in,  355 
of  sheet  metal  in  place  of  other  materials,  365 
of  special  fixtures  in  the  turret-lathe,  162 
tools,  advantage  in  the,  223 
Utility  of  milling  machines,  120 
doubt  of,  128 
of  the  sub-press,  462 

V 

Value  of  up-to-date  fixtures  and  machine  tools,  512 

Vertical  spindle  milling  machines,  127 

Vital  point  in  milling-machine  practice,  most,  236 

W 
Watek  or  fluid  dies,  474 
Way  to  construct  a  drawing  die,  370 

to  keep  note-books  of  shop  practice,  511 
Whitney,  Eli,  19 
Wiring  and  curling  processes,  474 

straight  work,  448 
Working  aluminum,  493 

Working-range  equipment  vs.  universal  equipment,  515 
Workman's  supplies,  39 
Work  not  to  be  jigged,  34 


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plates,  reduced  copies  of  which  are  shown  in  full-page  illustrations  in  the  text. 
500  pages.     Fully  illustrated. 

PARSELL  &  WEED.     Gas  Engine  Construction 

A  practical  treatise  describing  the  theory  and  principles  of  the  action  of  gas 
engines  of  various  types,  and  the  design  and  construction  of  a  half-horse  power 
gas  engine,  with  illustrations  of  the  work  in  actual  progress,  together  with  dimen- 
sioned working  drawings,  giving  clearly  the  sizes  of  the  various  details.  Second 
edition,  revised  and  enlarged.  Twenty-five  chapters.  Large  8vo.  Handsomely 
illustrated   and   bound.     300   pages.     $2.50. 

REAGAN,  JR.     Electrical  Engineers'  and  Students'  Chart  and  Hand  Book 
of  the  Brush  Arc  Light  System 
Illustrated.     Bound  in   cloth,   with   celluloid   chart   in   pocket.     $1.00. 

SLOANE.     Electricity  Simplified 

The  object  of  "Electricity  Simplified"  is  to  make  the  subject  as  plain  as  pos- 
sible and  to  show  what  the  modern  conception  of  electricity  is.  158  pages.  Illus- 
trated.    Tenth   edition.     $1.00. 

SLOANE.     How  to  Become  a  Successful  Electrician 

It  is  the  ambition  of  thousands  of  young  and  old  to  become  electrical  engineers. 
Not  everyone  is  prepared  to  spend  several  thousand  dollars  upon  a  college  course, 
even  if  the  three  or  four  years  requisite  are  at  their  disposal.  It  is  possible  to 
become  an  electrical  engineer  without  this  sacrifice,  and  this  work  is  designed  to 
tell  "How  to  Become  a  Successful  Electrician"  without  the  outlay  usually  spent 
in  acquiring  the  profession.     Twelfth  edition.     189  pages.     Illustrated.     Cloth.     $1.00. 

SLOANE.     Arithmetic  of  Electricity 

A  practical  treatise  on  electrical  calculations  of  all  kinds,  reduced  to  a  series 
of  rules,  all  of  the  simplest  forms,  and  involving  only  ordinary  arithmetic;  each 
rule  illustrated  by  one  or  more  practical  problems,  with  detailed  solution  of  each 
one.     Sixteenth   edition.     Illustrated.     138  pages.     Cloth.     $1.00. 

SLOANE.     Electrician's  Handy  Book 

An  up-to-date  work  covering  the  subject  of  practical  electricity  in  all  its 
branches,  being  intended  for  the  everyday  working  electrician.  The  latest  and 
best  authority  on  all  branches  of  applied  electricity.  Pocket-book  size.  Hand- 
somely bound  in  leather,  with  title  and  edges  in  gold.  800  pages.  500  illustra- 
tions.     Price,    $3.50. 

SLOANE.     Electric  Toy  Making,   Dynamo  Building,  and  Electric  Motor 
Construction 

This  work  treats  of  the  making  at  hom$  of  electrical  toys,  electrical  apparatus, 
motors,  dynamos,  and  instruments  in  general,  and  is  designed  to  bring  within 
the  reach  of  young  and  old  the  manufacture  of  genuine  and  useful  electrical 
appliances.      Fifteenth    edition.      Fully   illustrated.      140   pages.      Cloth.      $1.00. 


Publications   of  The    Norman  W.    Henley   Publishing  Co. 

SLOANE.     Rubber  Hand  Stamps  and  the  Manipulation  of  India  Rubber 

A  practical  treatise  on  the  manufacture  of  all  kinds  of  rubber  articles.  146 
pages.     Second   edition.     Cloth.     $1.00. 

SLOANE.     Liquid  Air  and  the  Liquefaction  of  Gases 

Containing  the  full  theory  of  the  subject  and  giving  the  entire  history  of 
liquefaction  of  gases  from  the  earliest  times  to  the  present.  It  shows  how  liquid 
air,  like  water,  is  carried  hundreds  of  miles  and  is  handled  in  open  buckets.  It 
tells  what  may  be  expected  from  it  in  the  near  future.  365  pages,  with  many 
illustrations.     Handsomely   bound   in   buckram.      Second   edition.     $2.50. 

SLOANE.     Standard  Electrical  Dictionary 

A  practical  handbook  of  reference,  containing  definitions  of  about  5,000  distinct 
words,  terms,  and  phrases.  An  entirely  new  edition,  brought  up  to  date  and 
greatly  enlarged.  Complete,  concise,  convenient.  682  pages.  393  illustrations. 
Handsomely  bound  in  cloth.     Svo.     $3.00. 

USHER.     The  Modern  Machinist 

A  practical  treatise  embracing  the  most  approved  methods  of  modern  machine- 
shop  practice,  and  the  applications  of  recent  improved  appliances,  tools,  and 
devices  for  facilitating,  duplicating,  and  expediting  the  construction  of  machines 
and  their  parts.  A  new  book  from  cover  to  cover.  Fifth  edition.  257  engravings. 
322  pages.     Cloth.     $2.50. 

VAN  DERVOORT.     American  Lathe  Practice 

This  is  a  new  book  from  cover  to  cover,  and  the  only  complete  American  work 
on  the  subject,  written  by  a  man  who  knows  not  only  how  work  ought  to  be 
done,  but  who  also  knows  how  to  do  it  and  how  to  convey  this  knowledge  to 
others.  It  is  strictly  up  to  date  in  its  descriptions  and  illustrations,  which  repre- 
sent the  very  latest  practice  in  lathe  and  boring-mill  operations  as  well  as  the 
construction  of  and  latest  developments  in  the  manufacture  of  these  important 
classes  of  machine  tools.  A  large  amount  of  space  is  devoted  to  the  turret  lathe, 
its  modifications  and  importance  as  a  manufacturing  tool.  320  pages.  200  illus- 
trations.    $2.00. 

VAN  DERVOORT.  Modern  Machine  Shop  Tools;  Their  Construction, 
Operation,  and  Manipulation,  Including  Both  Hand  and  Machine  Tools 
A  new  work,  treating  the  subject  in  a  concise  and  comprehensive  manner.  A 
chapter  on  gearing  and  belting,  covering  the  more  important  cases,  also  the 
transmission  of  power  by  shafting,  with  formulas  and  examples,  is  included.  This 
book  is  strictly  up-to-date  and  is  the  most  complete,  concise,  and  useful  work 
ever  published  on  this  subject.     Containing  552  pages  and   673  illustrations.     $4.00. 

WOOD  WORTH.  Dies,  Their  Construction  and  Use  for  the  Modern  Work- 
ing of  Sheet  Metals 
A  practical  work  on  the  designing,  constructing,  and  use  of  tools,  fixtures,  and 
devices,  together  with  the  manner  in  which  they  should  be  used  in  the  power 
press  for  the  cheap  and  rapid  production  of  sheet  metal  parts  and  articles.  Com- 
prising fundamental  designs  and  practical  points  by  which  sheet  metal  parts  may 
be  produced  at  the  minimum  of  cost  to  the  maximum  of  output,  together  with 
special  reference  to  the  hardening  and  tempering  of  press  tools  and  to  the  classes 
of  work  which  may  be  produced  to  the  best  advantage  by  the  use  of  dies  in  the 
power   press.     Fourth  edition.     400  pages.     500   illustrations.     $3.00. 

WOODWORTH.     Hardening,  Tempering,  Annealing,  and  Forging  of  Steel 

A  new  book  containing  special  directions  for  the  successful  hardening  and 
tempering  of  all  steel  tools.  Milling  cutters,  taps,  thread  dies,  reamers,  both 
solid  and  shell,  hollow  mills,  punches  and  dies,  and  all  kinds  of  sheet-metal 
working  tools,  shear  blades,  saws,  fine  cutlery,  and  metal-cutting  tools  of  all 
descriptions,  as  well  as  for  all  implements  of  steel,  both  large  and  small,  the  sim- 
plest and  most  satisfactory  hardening  and  tempering  processes  are  presented.  The 
uses  to  which  the  leading  brands  of  steel  may  be  adapted  are  concisely  presented, 
and  their  treatment  for  working  under  different  conditions  explained,  as  are  also 
the  special  methods  for  the  hardening  and  tempering  of  special  brands.  320  pages. 
250  illustrations.     $2.50. 

WOODWORTH.   Modern  Tool  Making  and  Interchangeable  Manufacturing 

This  book  is  a  complete  practical  treatise  on  the  art  of  American  tool  making 
and  system  of  interchangeable  manufacturing  as  carried  on  to-day  in  the  United 
States.  In  it  are  described  and  illustrated  all  of  the  different  types  and  classes 
of  small  tools,  fixtures,  devices,  and  special  appliances  which  are  or  should  be  in 
general  use  in  all  machine-manufacturing  and  metal-working  establishments 
where  economy,  capacity,  and  interchangeability  in  the  production  of  machined 
metal   parts   are  imperative. 

It  is  a  practical  book  by  an  American  toolmaker  for  practical  men,  written 
and  illustrated  in  a  manner  never  before  attempted,  giving  the  twentieth  century 
manufacturing  methods  and  assisting  in  reducing  the  expense  and  increasing  the 
output  and  the   income.     400  pages.     600  illustrations.     $4.00. 


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